I second this. Don't know how it works for iOS, but for Android it is straight-forward. And should be even more now with the new automatic backup for Android M [0].
You would have people keep their data as they update devices, no need to build an API, but would lose the analytics part that you mentioned.
You would have people keep their data as they update devices, no need to build an API, but would lose the analytics part that you mentioned.
[0] http://developer.android.com/preview/backup/index.html#overv...