I have Facebook integration work very well in iOS with the following features:
Sign in and requesting permissions, Sign out, testing for being signed in, failed sign in, accessing user data obtained via permissions, sharing by posting to their profile (text, images), displaying their profile picture in an active. The sign in doesn't use the Facebook UI it's simply a call to login via web (no Facebook app present) or the Facebook App.
I have not done it as an extension I kind of cheated by building off two extensions that are cross-platform and have actions, expressions that are ripe for replacing on the Objective-C side. I have written no tutorial and I haven't looked at the in App ads yet. I guess the big point is that it can be done and relatively with ease.
I heard someone was working on an extension ... my question is how was this possibly that big of a challenge? When will this be official?
I may post a high level how-to eventually but for now we really need this formalized ASAP. Social interaction is a major requirement for games today.