6) is mandatory. Add at least one from 1) 2) or 3) If your app is heavily dependent upon fb, make it known upfront about what the app uses facebook for, and on

6) is mandatory. Add at least one from 1) 2) or 3) If your app is heavily dependent upon fb, make it known upfront about what the app uses facebook for, and only then use it as the only option. 4) & 5) would not be much appreciated and used options IMO for such an app.