Screen fragmentation was a large problem even before Android. When I was first learning to program, one of the platforms I initially targeted was Windows Mobile

Screen fragmentation was a large problem even before Android. When I was first learning to program, one of the platforms I initially targeted was Windows Mobile, version 6.0. On this platform fragmentation was limited because there were only so many devices developed for Windows Mobile (although screen resolutions were generally different for QVGA vs non-QVGA screens, and smartphones with keyboards had smaller resolutions). Nevertheless, fragmentation was still a problem. Without an api adequate for handling different screen sizes and resolutions, it was hard to develop an application for one device then port it to other devices. I use the term "port" because usually this was actual porting; in some cases it would have been better to have a separate binary for each target device than to have a single binary for all devices. I think the reason Windows Mobile developers were so rare compared to developers for emerging platforms like iOS and Android despite Windows Mobile having been around longer is that the alternatives learned from WM's poor example to create better apis. When I switched from Windows Mobile to playing around with Android 2.1, there was so much more I could do with layouts and the simulator in the IDE to target more devices. Newer versions of iOS, Android 4, Windows Phone, and others have all been improved in this regards even more, to the point that I now think of screen fragmentation as something of a non-issue when I tinker with mobile apps.