By the way, someone else commented further down that Apple doesn't allow third party apps to use it for realtime (video chat). But I can't verify if that's true or not.
Apple doesn't facilitate realtime use through AVFoundation, but there are workarounds. Apple doesn't specifically restrict realtime use and does approve apps using the workarounds.
By the way, someone else commented further down that Apple doesn't allow third party apps to use it for realtime (video chat). But I can't verify if that's true or not.