I can add the new facebook framework to my project with the new XCode 4.5.2 but I guess it won’t work? I don’t have access to a device with iOS 4 nor 5 (have simulator of 5). I only need to do Facebook share (post a status from my app).
What strategy should I use to make sure I get facebook share in all platforms (iOS 4, ios 5, ios6)? Right now we are using FacebookManager
The normal Facebook iOS SDK, from Facebook, will work perfectly fine on all versions of iOS. You should just use that. It will use native auth on iOS 6 and fall back gracefully to switching to the FB app or Safari as appropriate.