In addition to Colin's remarks (which are great and apply to both
Android and iOS), here is a bit more detail for Android:* Variety is the
key. Your first few test devices should be very different from each
other not only in screen size, but also in manufacturer, Android
version, and screen density.* Definitely include a Samsung phone, not
only because they sell well (so your customers will likely have them),
but also because Samsung tweaks Android in ways that surface bugs we
don't see in other...