Making apps for Android can seem kind of messy because of the big scary F-word: Fragmentation. It's part of why Tim Cook might call Android a "toxic hellstew" on stage. But the dirty little secret? It's really not that bad, at least when it comes to screen size.
You've probably seen scary graphics laying bar how many different Android screen sizes are out there. They aren't uncommon! They're also not that accurate, as PocketCasts developer Russell Ivanovic explains on his blog. All those screen sizes actually aren't so different after all.
Seems like a lot of variation, right? The part that might confuse most non-developers, is we lay everything out at '1x' or '1dp'. So on the iPhone you can have a 320×480 pixel iPhone 3G, and a 640×960 iPhone 4, but the interface itself doesn't change, it's still 320×480. You don't have to re-lay out any buttons or do a custom interface for it. All you do is provide higher resolution assets to make things look crisper. The same is true on Android.
And with that in mind, those busy graphics (like the one at the top of this post) wind up looking a little more like this:
Of course that's just one piece of the puzzle. We're only talking about phone screen sizes now, not tablets. And screen size isn't the only part of fragmentation; many, many Android phones are running old versions of the operating system as well, and will likely never get updated, which means developers still have to accommodate a wide range of systems (or leave their customers behind).
But if anyone tells you that the variety of Android phone screen sizes out there is terrifying and bad and a big problem for Android devices as they exist today, don't pay them much mind. It's really not that big of a deal. And as time goes on, it's only getting better. [Rusty Rants]