WHAT TO LOOK FOR IN A
              SMARTPHONE/TABLET
    
    
      It's very difficult to make an intelligent and informed choice
      when purchasing a smartphone or tablet, especially if you've never
      owned one before.  The following is a list of features to
      look for, each with a discussion of why they're important.
      
      Tablets and smartphones are both "portable devices" and operate
      similarly using the same operating systems and apps, with two
      distinctions:  First, anything with a 6" screen or smaller is
      a smartphone, while anything with a 7" screen or larger is a
      tablet.  The more puzzling distinction, though, is that you
      cannot use a tablet as a phone.  It may or may not have 3G or
      4G/LTE data service, which means it's getting data via a cellphone
      service, and it has speakers and a microphone, but it cannot be
      used as a phone.
      
      OPERATING SYSTEM:  Arguably the most important
      decision, as it forever locks in your selection of apps.  In
      general, there are four popular operating systems:  Apple,
      Android, Kindle, and Windows.
      
      Android is an "open-source" operating system, meaning that
      although Google maintains the license and the database, it's free
      for anyone to use, and anyone can write apps for use with
      it.  This leads to a bit of "wild west" in the market for
      apps, with an overwhelming array of titles to choose from. 
      Some apps are free, some cost a few bucks -- often after a free
      trial period -- and some are supported by advertisements.  It
      can be startling to see an advertisement come up on your
      phone.  Many of the advertiser-supported ones offer an option
      that you can pay a few bucks to make the ads go away.  Even
      when you pay for your apps, you'll find them far more
      reasonably-priced than software for your PC ever was.
      
      The other three operating systems are proprietary, meaning you
      have to deal with the organizations involved for apps.  The
      implications vary.
      
      Apple is immensely popular, and the public can submit apps, but
      all apps must be tested and approved by Apple.  This is what
      many people like about Apple; you're not likely to get
      buggy or virus-infested apps from them.  Still, many Apple
      device owners speak of "jailbreaking" their phones so they can
      load non-Apple-approved apps.
      
      Kindle uses a "forked" version of Android.  To be
      clear:  IT IS NOT ANDROID.  Because Android is
      open-source, Kindle freely copied its structure and modified it
      for its own use.  And that modification means you cannot load
      Android apps; you must get your apps from Kindle.  Kindle
      sells its tablets at a loss and then charges enough for its apps
      to make up for it.  Do you think this is an acceptable
      business plan?
      
      Windows is a whole 'nuther idea in operating systems:  Rather
      than creating a clean sheet operating system designed from the
      ground up for portable devices, MicroSoft devised its tablets and
      its operating system to interact and coexist with its PC operating
      system.  Many commercial users find this ideal.  First
      off, they don't need to retrain their employees on a new system,
      and second their files can be opened and worked with on either
      type device.  MicroSoft promotes its tablets as being capable
      of doing real work.  All of this is valuable, but note that
      these benefits will diminish with time as Android and Apple
      systems develop further and apps are introduced that facilitate
      translations from PC's to portable devices.
      
      OPERATING SYSTEM UPDATES:  The apps you install will
      update automatically, but the operating system may not -- at
      least, not with an Android device.  Usually, the Android
      version your device comes with is the one you'll be stuck with
      until you buy a newer device.  The only way to update to a
      later release is if the device manufacturer issues an
      update.  At least one manufacturer claims that every time a
      new release of Android comes out, they will publish an update so
      owners of their products can always be using the latest operating
      system.  Shame on all the manufacturers who are not
      making this promise.
      
      CAMERA:  All of these devices have cameras these days;
      most of them have two, one facing the user and a better one facing
      away from the user.  While most features on a portable device
      are either-you-have-it-or-you-don't, the camera is where you
      really need to be concerned about the quality of the
      feature.  Allow me to illustrate the importance:  In
      five or ten years, you'll probably move on to a new smartphone,
      but you'll probably want to keep some of the pictures you've taken
      with it forever.  Pictures of people who have since
      died, places you'll never go again, the hair you once had -- these
      memories are likely to be of great importance to you
      someday.  If you've taken all those photos with a lousy
      camera, you'll regret it for the rest of your life.  You
      could carry around a good digital camera separate from your phone,
      but nobody actually does.  When something happens, especially
      something unexpected, it's your smartphone you're going to whip
      out to capture it for posterity.  You want the best camera
      you can get, period.
      
      The first indication of quality in a camera is the number of
      megapixels.  Your HDTV is 1920x1080 resolution, meaning
      2,073,600 pixels or 2 megapixels.  Any decent smartphone
      camera will be 5 megapixels or more.  Sometimes when you take
      a picture, what you really wanted was just in the center of the
      image, so you crop away 3/4 of the image -- and your 5 megapixel
      image just became a 1.25 megapixel image.  You can't have too
      many megapixels, but remember that more megapixels means the photo
      takes up more data storage space.  You can reduce the
      resolution later to reduce the data storage requirements, although
      most find it easier and better to just buy more data storage
      space!  It seems to get cheaper every day.
      
      Note:  The default resolution that the camera uses may not
      be its maximum resolution.  Often, the maximum resolution may
      be a nearly square image while the default is an image the same
      shape as the smartphone's screen.  That means that the
      default is cropping off part of the image to fit your smartphone
      screen.  You might as well change the default to take the
      entire image; you can crop it later if you wish.
      
      There are other things to look for in the camera, though. 
      One is a flash.  This author has a Moto e 4G/LTE smartphone
      that does not have a flash.  Not only can you not
      take pix in the dark, you also don't have the "flashlight" app
      that holds the flash continuously on to help you find your way
      around.  The only thing it can do is turn on the screen
      bright white, which isn't nearly as good.  Most devices seem
      to have a flash for the camera looking away from the user but not
      one facing the user.
      
      There's also zoom.  A mechanical zoom would be great, but
      apparently they don't fit in the narrow thickness of a
      tablet.  One company compensates by offering a 41 megapixel
      camera (!) which means you can crop 90% of the photo away and
      still have a 4 megapixel image.  Theoretically at least, this
      is the same thing as a 4 megapixel camera with a 3X zoom. 
      And, to be clear, this is exactly the same thing a digital zoom
      does; it just crops part of the image before you even take the
      picture.  You can also buy, for a few bucks, a little 2X
      telephoto lens that you can stick over your device lens, held
      either by magnet or by a big spring clip; these work OK but
      they're not convenient to carry around with you, and they're not
      convenient to get out of your pocket and affix to your device
      while an airplane is crashing or whatever.
      
      There's even focus.  Most of these cameras don't even have
      any sort of mechanical focus.  Apple has reportedly come out
      with one with a real mechanical focus using a nearly microscopic
      motor.  Hopefully others will follow suit.
      
      When shopping for a device, nothing beats just taking some
      pictures and seeing how they come out.  You can usually do
      this in the store.  Don't just look at the screen, though;
      they'll always look good that way.  Rather, find the zoom
      function and zoom in on the picture you just took and see how the
      details look when blown up to fill the screen.  Take pix of
      something close up, and take pics of things moving (like ceiling
      fan blades), as these present specific challenges to cameras.
      
      These cameras can also be used to record video, again with varying
      levels of quality.  A good baseline would be HDTV quality,
      which is 2 megapixels recording at 60 frames per second. 
      That's hard, though; it takes premium processing power to get that
      many frames per second, so some compromise at half that, 30 frames
      per second.  You'd be hard-pressed to tell the difference,
      since the human eye only sees about 16 frames per second. 
      Still, if you try to play that video back in slow motion, the
      lower frame rate will become apparent.  Better systems should
      be able to record video at the new 4K resolution, which is 8
      megapixels.  All of this will make your videos look really
      good on America's Funniest -- or when you're showing them to your
      grandchildren 40 years from now.
      
      GPS:  GPS stands for Global Positioning System. 
      It's a system of satellites in low Earth orbit with atomic clocks
      on board that emit signals that can be picked up by a handheld
      device and used to determine your location to an accuracy of
      roughly 30 feet.  Good enough for targeting missiles and
      bombs, which is what it was originally intended for.  Since
      inception it's been supplemented with WAAS, an on-the-ground local
      correction, which improves the accuracy to about 10 feet depending
      how close you are to the WAAS station.  Good enough for
      landing airplanes.  The next generation of satellites is
      already planned, and accuracy will be within millimeters, good
      enough for tracking plate tectonics.
      
      Many people believe a "GPS" is a device that sits on the dashboard
      of your car and presents a map and has
      a voice that tells you when to turn.  That's a
      navigation system and it's one application of a GPS, but not the
      only one.  Some GPS devices have no maps at all and merely
      provide an arrow and a distance to a set destination; you have to
      figure out for yourself how to get there.  This latter type
      is more appropriate in the woods than on the highway.
      
      If you buy a smartphone in the US, it has GPS.  It's required
      by law so that a 911 operator can pinpoint your location in the
      event of an emergency.  You can turn off the "location
      services" so your apps don't have access to the GPS, which some
      people do because they're convinced that Big Brother is tracking
      them, but you cannot turn off the GPS itself; if you call 911 with
      that smartphone, the operator will know where you are.
      
      The same is not true for a tablet.  Since a tablet cannot be
      used as a phone, whether or not it has a GPS is optional, and if
      it has GPS you can turn it off to save battery life.  Many
      Kindles do not have GPS; they try to fake it using the location
      data of wi-fi servers in the vicinity.  This works OK in the
      big city but not so well in the woods where you really need it.
      
      As long as your device has GPS, you don't need to buy that
      navigation system for your car.  Your smartphone or tablet
      will do the job, including providing voice commands.  Just
      download the appropriate app and set the device on the
      dashboard.  You can also download maps for it and update them
      as required, often for free.  There are even versions that
      will operate as a "heads-up display": set the tablet on top
      of the dashboard and look at the reflection of the display in the
      windshield as you drive.
      
      You don't need a speedometer either, actually.  Your device
      can tell you how fast you're going, and more accurately than the
      speedometer in your car.
      
      MEMORY CARD PORT:  The Android operating system takes
      about 3-4 GB of data storage space on your device.  If the
      device came with 8GB built in, you have 4-5GB of available space
      to store your stuff.  If it came with 16GB, you have 12-13GB
      of space to play with.
      
      That internal data storage space is a good place to store your
      apps.  It is not a good place to store your photos or
      other items of personal importance to you.  If your device
      gets smashed or stolen, it's gone.  Buy a new device and you
      can just install all your apps again in a matter of minutes, but
      you'll never get those photos back.
      
      A better idea is to buy a 16GB microSD memory card and plug it
      into a memory card port on your device.  It won't help if
      it's stolen, but it will help if it's broken; you can just unplug
      the memory card from a broken device and plug it into a new device
      and you're good to go.  Within the Settings menu you can find
      options to select what gets stored in the internal memory and what
      goes on the card; if the internal memory gets full, just move some
      stuff to the card.  That memory card port actually gives you
      infinite data space; if you ever fill up that 16GB card you can
      just buy more 16GB cards and swap them in and out.  A microSD
      card is about the size of your pinky fingernail, so the toughest
      thing about swapping them in and out is not losing them in the
      couch cushions.
      
    
    
     
     
      Note:  MicroSD cards are available up to at least
      256GB.  However, your device may not be able to make use of
      that much capacity.  Check the specs on your device; if it
      says something like "16GB expandable to 32GB", it's trying to tell
      you that anything larger than a 16GB memory card won't work in it.
      
      The other idea is to use "the cloud", basically using an online
      storage provider as your personal storage space.  Snap a pic
      and it automagically uploads to this site, and you can retrieve it
      to look at it just as easily.  Even if your device gets
      stolen, your photos are safe.  Online
          presents its own issues, though; make very sure to use a
          password that nobody would guess in a million years if you
          don't want your bank account information to end up in the
          hands of the Chinese.  Note: 
      If you're having to pay by the byte for your data plan, you
      definitely do not want to use cloud storage as it will run
      up data charges moving your files in both directions.
    
      Key point:  Some smartphones and tablets don't have a memory
      card port!  Google's own Nexus tablets don't, for example,
      because they expect you to utilize their cloud.  For me, the
      lack of a memory card port is a deal breaker, but you can decide
      for yourself.
    
    Anything really important you should be backing up
          anyway, either to some storage device at home or someplace
          online.  For just a couple of bucks you can buy a USB OTG
          cable (see below) or adapter that plugs into your device's
          charging/data port and enables you to plug in a USB thumb
          drive or any of several other types of data storage systems,
          so backing up your important stuff shouldn't be
          difficult.  Just remember to do it every now and then.
      
      DATA/CHARGING PORT:  Smartphones have a small
      data/charging port that's actually a standard, you can buy cords
      to fit it anywhere.  Large tablets go a different route,
      though, and have a broad, flat plug.  The reason is that the
      standard plug is rated to handle only 0.5 amps charging current,
      but large tablets will draw 2.1 amps.  Apple tablets use one
      of these broad connectors, and their products are common enough
      you can buy suitable cords in Walmart.  Samsung Galaxy
      tablets use a broad plug that looks exactly like the Apple
      connector, but it's not; neither one can be used with the other
      manufacturer's device.  If you have a Samsung tablet, don't
      just buy a cord with a connector that looks right; make sure it's
      actually intended for a Samsung rather than an Apple.
      
      CHARGER:  All of these devices charge at 5VDC because
      that's the standard power supply in a USB port.  Smartphones
      typically charge at 0.5 amps, and such chargers have become
      ubiquitous -- you can buy one from a bin in the checkout line at
      the Dollar store.  Some smartphones don't even come with a
      charger to save money, presuming you already have one! 
      Remember, though, that you probably want two -- one that
      plugs into a wall outlet in your house and one that plugs into the
      cigarette lighter in your car.  You may also need a suitable
      cable to connect the charger to the smartphone; such cables are
      also easy to find in a Dollar store.
      
      If you have a tablet, things get trickier.  A tablet draws
      more current -- 2.1 amps seems pretty standard -- which is more
      than the cheapo Dollar store chargers can provide.  Worse,
      though, is the fact that a couple of those cheap chargers have
      caught fire or melted down when overloaded and damaged somebody's
      car or something, and the tablet company got sued for it!  So
      now both a Samsung and an Apple tablet will detect whether your
      charger is up to the task, and if not they will only draw
      0.5 amps from them.  That big screen alone draws more than
      0.5 amps, so if the tablet is powered up it will gradually be
      draining the battery even though it's plugged in.  The tiny
      battery symbol in the corner on the screen on a Samsung tablet
      will have a red X in it to indicate the charger isn't keeping
      up.  If the tablet is turned off it will charge the battery
      eventually, it'll just take a long time to do it.  What you
      really want is a charger rated at 2.1 amps.  They're not too
      difficult to find, but note that some of them still don't really
      charge too well.  You want to look for a quality product
      there.
      
      USB PORT:  The USB connector is a really handy
      standard, allowing one to connect your keyboard, mouse, printer,
      whatnot to your PC all with the same connector.  Then Apple
      and Android portable devices appeared without such
      ports!  Almost inexcusable, but it's probably because they
      wanted the devices to be thin and the standard USB port is too
      thick and bulky.  You can buy a jumper that you can plug into
      your data/charging port that will allow you to plug in a USB
      device or thumb drive.  It's called a "USB OTG cable", OTG
      standing for "on the go".
      
    
    
     
    
      You'll also have to download an app to make it usable, as the
      device probably doesn't come with the capability of recognizing
      USB devices.  MicroSoft, meanwhile, does include USB ports in
      their Windows tablets -- a valuable selling point.
      
      WI-FI:  Wi-Fi is a standard for short-range wireless
      communication, typically good for 100 feet or so.  It can be
      used to connect computers within an office, or to connect a
      computer to a printer in the next room.  It can be used to
      connect portable devices to one another, including transferring
      files from an Apple device to an Android device when there are no
      cords that could connect the two.
      
      When most people use the term "wi-fi", though, they're referring
      to one particular application of this wireless standard:  The
      use of a "router" hard-wired into the internet to provide wireless
      internet connectivity to devices within range.  You can walk
      into your local Burger King, grocery store, or library and there's
      a good chance they provide free wi-fi service, just log in and
      agree to their terms.  Wi-fi is so common you can typically
      just drive down the street and several will appear on your device
      as being within range.  It is very, very easy to find free
      wi-fi service in most urban areas.  What's more, nobody
      bothers to turn their wi-fi off when they close for the evening,
      so you can often park outside a business at 3 in the morning and
      make use of their wi-fi.
      
      Many wi-fi systems are password protected, though; you can't
      connect to them without knowing the password.  It'll tell you
      when you look at the list of wi-fi's within range which ones are
      secured.  If you are the owner of the router, you may
      choose to password protect it to prevent strangers from using it
      and running up your data bill or from simply tying up the system
      so it runs slower for you.  Many people have internet service
      that doesn't keep track of how much data is used, so they'll just
      leave the wi-fi open deliberately so anyone within range can use
      it.  Finally, there are organizations that offer wi-fi
      connectivity for a fee; you'll see that when you try to log on,
      and if you're not interested you can tell your device to forget
      those.
      
      There are actually two standards for wi-fi:  IEEE 802.11(a)
      and 802.11(b/g).  These operate on different
      frequencies.  Most routers provide both, and when you connect
      your device will connect to whichever at random, or sometimes
      both.  This author owns a Moto e 4G/LTE that has only
      802.11(a) capability.  Normally one wouldn't notice, but I
      happened to be in a Hardee's where everyone else was using the
      wi-fi with no problem but I couldn't connect.  It turned out
      the 802.11(a) portion of their router was malfunctioning, and I
      was the first customer who noticed.
      
      Beware of "spoof" wi-fi providers.  A wi-fi connection in
      itself is secure, nobody can hack into the communication between
      you and the wi-fi router.  But crooks get around that by
      providing their own wi-fi router and making it look like
      something trustworthy.  Like, they'll give it the name of a
      motel nearby so you think you're connecting to the motel's
      wi-fi.  But when you connect, they can monitor everything you
      do.  If you log into your bank account using your password,
      they now know your bank account number and your password. 
      Not good.  They can even wander around in the files on your
      device, so it's good to have the really important ones password
      protected.
      
    CELLULAR DATA:  When you sign up
          for a cell phone service, your contract will usually include
          terms for talk, text, and data.  Data is what you need to
          use the internet.  You can get data either via your cell
          phone service or via wi-fi, but the wi-fi is only usable
          within 100 feet or so of a wi-fi router whereas the cellular
          data is usable anywhere with cell phone service.  Wi-fi
          is often free while cellular data usually has costs associated
          with it, so your device may be capable of automatically
          choosing to use wi-fi when it's available.
          
          Obviously, all smartphones will have cellular capability, and
          hence can utilize a cellular data plan.  Tablets might
          not have cellular data capability at all, however; in fact,
          it's sometimes a rather expensive option.  It's possible
          to buy a device to add cellular data capability to your
          tablet; the "hotspot" discussed below is one such option.
          
          The speed of the cellular data capability is indicated by the
          "generation":  2G, 3G, or 4G/LTE.  2G is basically
          dial-up speed, it's painfully slow but better than
          nothing.  3G is an order of magnitude faster than 2G, and
          4G/LTE is an order of magnitude faster than 3G.  It's
          called 4G/LTE because it really doesn't meet the requirements
          originally set out as being "4G", but nothing does yet, LTE is
          the best we've got.  In this day and age, there's no
          excuse for buying a smartphone that doesn't have 4G/LTE
          capability.
           
        HOTSPOT:  A hotspot is wi-fi turned
      around, where your device becomes the source of the
      internet connectivity rather than the user.  Your device is
      connected via its cellular data connection, and then makes that
      data available via wi-fi so that other devices can log
      on.  This is really slick, and can provide wi-fi service in a
      moving car or waaay out in the woods.  Some cars now come
      with a hotspot built in at the factory, and spend millions of
      dollars in advertising proudly telling you you're buying a car
      with a feature you already have in your shirt pocket.  Of
      course, you have to pay for the cellular data service.  You
      probably want a secure password on your hotspot so strangers
      cannot use your data.
      
      The original idea for hotspots was a specialized device, something
      you set up in your home or car and permanently wire in.  But
      it was quickly realized that a smartphone could do the job since
      it has wi-fi and cellular data capabilities.  On early
      smartphones you'd download a hotspot app, but on later models the
      feature comes built-in.
      
      I'm pretty sure that any smartphone can be used as a
      hotspot.  The data plan is another story.  Many cellular
      service providers want to make money providing hotspots and
      deliberately prevent you from using your smartphone as a
      hotspot; when you try to turn the hotspot on, it goes through a
      verification step to check if your cellular provider permits that,
      and if it doesn't you're outta luck.  You either have to pay
      extra, or worse you may have to purchase a separate device. 
      If you intend to use your smartphone to provide a hotspot, make
      very sure your service provider permits this before signing
      up.  As an example, as of this writing SmartTalk Wireless
      does not permit their data to be used to run a hotspot,
      while Verizon Prepaid does.  This is interesting, as
      both operate on the same network, Verizon's.  SmartTalk
      charges the same monthly fee but provides 5GB of data rather than
      2GB, and slows down when you exceed that limit rather than shuts
      it off altogether as Verizon does.  All that sounds like
      SmartTalk is a much better deal -- until you realize that to use
      SmartTalk as a hotspot you'll need to pay another monthly fee,
      whereas you can just go ahead and use the Verizon Prepaid service
      for a hotspot.
      
      This author uses his Moto e 4G/LTE as a hotspot, and it's worth
      noting that the range of that wi-fi hotspot is considerably less
      than that of a typical wi-fi router -- only perhaps 15-20
      feet.  Since the hotspot is a cell phone, that's not really
      an issue; just move the phone closer to the computer or whatever
      that you're connecting to the hotspot.  If, however, you
      intend to provide internet connectivity all over a house so that
      everyone can log in in their bedrooms, be aware that a single
      smartphone hotspot probably won't work very well.  You'll
      either need multiple smartphones or a different scheme.
      
      Note:  When a call comes in, the hotspot shuts off as soon as
      it starts ringing.  Whatever is happening on your wi-fi comes
      to a stop, and you'll start getting connection errors if you try
      to open new pages or download files.  As soon as the phone
      call is disconnected, the hotspot resumes operation.
      
      By the way, when using your smartphone as a hotspot, it doesn't
      have to be wi-fi.  It can also provide internet connectivity
      via Bluetooth (see below) or by being connected to your computer
      via a USB cable.
      
      BLUETOOTH:  Bluetooth is another standard for
      short-range wireless communication, even shorter range than
      wi-fi:  around 20 feet or less.  Its intention was to
      eliminate the need for wires connecting your keyboard, mouse, and
      headphones to your computer.  Since bluetooth accessories are
      typically battery powered, the standard is deliberately designed
      to maximize battery life.  The batteries in the accessories
      will typically last a year or more.
      
      If you own a laptop computer, you know there are ports and sockets
      all over the thing for plugging in various accessories. 
      Smartphones and tablets are the opposite; they may have only one
      data/charging port and one headphone connection.  Anything
      else you wish to connect will probably need to be either a wi-fi
      device or a bluetooth device.  This author has a bluetooth
      keyboard and a bluetooth mouse that work wonderfully with his
      smartphone and tablet.  The only trick is convincing the
      device to not bring up that onscreen keyboard when using the
      bluetooth keyboard; there's an app for that.  And it should
      be noted that the mouse is faking some of its functions, since an
      Android device doesn't even have some of the same functions that
      were on the PC that the mouse was intended for.
      
      Bluetooth accessories tend to be rather tricky to set up. 
      The instructions often involve something that sounds nutty, like
      pressing and holding all three buttons on the mouse at the same
      time.  Once set up, though, you never need to fiddle with it
      again; your device and your accessory will remember each
      other.  You should change the name on the accessory to
      something personal like "Joe's mouse" just in case you're ever in
      a room where others are using similar accessories; don't just use
      the default name.  
      
      Note that there are a lot of "wireless" mice on the market that
      are not Bluetooth.  They use a "dongle", a tiny
      receiver that plugs into a USB port on your computer and
      communicates wirelessly with the mouse.  Those won't work on
      a smartphone or tablet because there's no USB port to plug the
      dongle into.  You need to find true Bluetooth accessories.
      
      Bluetooth can also be used to connect one handheld device to
      another, to transfer files back and forth or the like.
      
      MOTION SENSORS:  Smartphones and tablets have motion
      sensors built in so they can tell when you're moving them. 
      Those same sensors have long been used in video game
      controllers.  When they first hit the market, it was
      surprising just how accurate they are, and it still can be amazing
      to watch them work.  The sensors in your smartphone, for
      example, are so accurate that you can install an app, set the
      phone on the passenger's seat in your car, and then floor the gas
      pedal and it'll tell you how many horsepower your engine has by
      sensing its acceleration!  There's even an app called MyShake
      that uses people's smartphones the world over to help track
      earthquakes.
      
      MAGNETIC FIELD SENSOR:  Better portable devices have a
      built-in magnetic field sensor.  You can download a compass
      app that turns your device into a compass.  That sounds
      simple until you try it; it's a really amazing compass, much
      better than that plastic thing you had in your Boy Scout days.
      
      Note, however, that many of the cases you can buy to protect your
      smartphone or tablet come with magnets built in to hold the case
      closed!  Those magnets render the built-in magnetic field
      sensor useless.  You'll need to either take the device out of
      the case or cut the magnets out to use the magnetic field sensor
      features.
      
      There are also telephoto lenses for use with the camera that
      attach to the device with a magnet.  There may be nothing on
      the device for a magnet to stick to, but the lens comes with a
      little peel-and-stick metal ring to attach permanently around the
      camera on the device so you can stick the lens on when you need
      it.  The metal ring isn't a problem for the magnetic field
      sensor, but the lens itself certainly is.  You'll have to
      leave that lens in the car or otherwise a good ways away if you
      want your magnetic field sensor to work properly.
      
      This author's Moto e 4G/LTE does not have a magnetic field
      sensor.  If you try to load a compass app, it tells you right
      away that the app won't work on this device.  There are
      compass apps that will fake it using the GPS sensors; when you
      move, the GPS knows which way you moved, and the app tells you
      which way is north accordingly.  It's far less accurate or
      useful than the real compass app, though.
      
      MICROPHONE:  A microphone is cheap, so all devices
      should have one.  It looks like a pin hole in the case. 
      Be sure not to cover it with a screen protector or whatnot. 
      There might be two microphones, one on the front and one
      on the back, with the one on the back side used for recording
      video with sound.
      
      SPEAKERS:  A smartphone has a speaker that you put up
      against your ear when talking, and it can work loudly enough to
      put your phone in speakerphone mode.  Tablets often have two
      speakers for stereo sound.  If you listen on headphones or
      earbuds, though, I believe you'll get stereo from any device.
      
      INFRARED EMITTER:  The author's Samsung Galaxy Note 10
      has an infrared emitter.  This enables the tablet to be used
      as a remote control for a TV, DVR, etc.  Of course, you don't
      need another remote, but what this thing can do goes far beyond
      that.  You can program it to turn the TV on and off, change
      channels, record programs on the DVR, whatever, all while you're
      not there.  Just leave the tablet on and laying on the table
      with the infrared emitter pointing towards the TV.  And if
      the internet is available, the tablet can search online listings
      for shows you want to see and record them for you.  Yet
      another feature you never knew you needed!
      
      STYLUS:  The difference between a Samsung Galaxy Tab
      and a Samsung Galaxy Note is that the Note comes with a stylus, a
      pen-looking thing that stores away in a little slot in the
      tablet.  It's got a really weird point on it that the screen
      can sense without even touching it!  It only needs to be
      within a millimeter or so.  It supposedly can be used for all
      sorts of features, including detailed drawing and writing (far
      less clumsy than trying to draw or write with your finger).
      
      Note that you can buy a "stylus" for use with a smartphone or
      tablet in any Dollar store, sometimes with a pen on the other
      end.  These are not the same thing; they are merely a
      simulated finger, a little black rubber dome on the tip that
      conducts electricity as well as a fingertip so the screen can
      detect its touch.  It helps a little, but it doesn't even
      keep fingerprints off the screen; the little black rubber dome
      leaves marks, too!  The stylus that comes with the Samsung
      Galaxy Note is completely different and provides a much more
      accurate pointing capability.
      
      NFC CHIP:  NFC stands for "Near Field Communication",
      and it's yet another short-range wireless communication standard
      -- this one is really short range, on the order of a few
      inches!  It's this function that enables you to transfer
      pictures from one smartphone to another by basically bumping them
      together.
      
      REPLACEABLE BATTERY:  Back in the day, anything that
      used batteries could have the batteries replaced -- even things
      that used rechargeable NiCad batteries since they were forever
      going bad.  With modern lithium batteries, however, many
      devices come with the battery built in and inaccessable. 
      This is an indication of how reliable lithium batteries are. 
      Still, being able to replace the battery is a good thing just so
      you can have two or more batteries and swap them out when one
      needs charging.  If your battery is inaccessable, it's still
      possible to work with a dying smartphone by carrying a spare
      battery pack that plugs into the phone's data/charging port. 
      It's just not as convenient as swapping out batteries.
      
      WIRELESS CHARGER:  Because it's just too tedious
      to have to plug your device into its charger, you can now get
      devices that you merely set on top of a charger and the battery is
      charged via induction.  Probably wastes energy, perhaps a
      nickel's worth of electricity a year.  Some owners have found
      the induction coil wrapped around the battery and concluded it was
      an antenna that the NSA was using to spy on them, which led to all
      sorts of idiotic conspiracy theories on Facebook.
      
       THUMBPRINT SENSOR:  Supposedly the ultimate in
      security, some devices now have a thumbprint scanner.  Do you
      really need it?  Perhaps not, but it might be easier and
      quicker to press your thumb against the scanner than to type in a
      lengthy and secure password when opening up your phone.
      
      One other thing to remember:  If you're relying on passwords
      for security, you have to be careful where you're standing when
      you type in that password.  Closed-circuit video cameras are
      everywhere these days, and you never know who's on the
      other end watching you.  They can just jot down your password
      for later after they steal you phone.  With a thumbprint
      sensor, you don't care who's watching.
      
      PAYMENTS:  Apple Pay and Google Pay are schemes by
      which you can use your device as a credit card.  Just wave it
      near the credit card reader at a checkout and it magically makes a
      payment for you.  As of this writing this is just getting off
      the ground here in the US, but it's certain to catch on; one less
      thing to carry.  Many people in Africa already rely upon
      smartphones for all their banking and money transfer needs.
      
      WATERPROOF:  There are only a couple of handheld
      devices that even claim to be waterproof, and of course they're
      making the most of it in their advertisements.  As well they
      should; the notion that any such devices were ever made that were
      not waterproof is shameful.  One's smartphone becomes
      part of one's life, you carry it around whereever you go and
      whatever you do.  It needs to be durable and sturdy, and that
      includes being waterproof.  Many of us put cases around our
      devices to help protect them, but that usually won't help if you
      drop them into the swimming pool.
      
      If you know there's a risk of your device getting wet, the thing
      to do is put it in a baggie -- a tough, reliable freezer bag type.
      
      ROUNDED EDGE:  The Samsung Edge comes with a glass
      screen that curls around the edge of the device.  Perhaps the
      single most pointless feature ever conceived.  Not cheap,
      either.  What you really want in a handheld device is
      a raised bezel around the glass screen so that you can set it face
      down on a flat surface without scratching the glass.  That
      won't help when setting it on nonflat surfaces, but there are so
      many flat surfaces in this world that such a bezel will
      dramatically reduce the amount of damage your screen suffers.
      
      HANDLE:  One really nice feature on a smartphone or
      tablet is a convenient handle or grip to hold it by.  Aren't
      those wonderful?  Can't answer that, because none of them
        have one!  Smartphones typically have a touch-sensitive
      screen all over the front and buttons down one or both sides so
      it's simply not possible to hold the %$^&^% thing without
      buttdialing somebody!  Tablets are even worse, having the
      same touchscreen and buttons but too large to easily grip between
      your thumb and fingers.  Hopefully, somebody will figure this
      out soon and start designing handheld devices to be handheld.