As with any API that is under active development, sometimes as an Android developer you'll come across a really neat feature which, it turns out, doesn't exist in earlier versions of the API and isn't backwards-compatible. There are a couple of ways to deal with this. One is simply to insist that users must have a given version, and to limit your app to that version. However, that can also limit the reach of your app â€“ there are still plenty of people out there using older versions of Android. Another option, for certain features, is to make use of the Android Support Library.