What operating system your customers are using is a big deal. It controls what features you can release and to some extent how things will look. The mixture of hardware and software is called fragmentation—and it’s a crazy huge number of combinations on Android and very few on Apple.

Here is an example of Android fragmentation from page 48 of Building a Mobile App:

And here is the latest reported Apple fragmentation:

via Apple Charts iOS Fragmentation, Dares People to Look at Android’s.