Well, there's the lack of design (or the lack of following the guidelines Google is now providing), then there's the compatibility things the devs need to do to support old(er) Android versions1, and then there are these small undocumented differences I seem to encounter every now and then.


  1. Using the compatibility features may lead to different results than when the devs do not need to have the compatibility support and they can use the more modern platform features.