While the AIR SDK offers a fairly comprehensive API, if you’re targeting mobile then you’re pretty much gonna have to rely on a few native extensions here and there. I’ve actually been pleasantly surprised by the number of quality extensions that have been produced by the community, and more continue to pop up every day.
If you’re looking for a comprehensive suite of iOS native extensions then you should take a look at the AIR Extensions website, which opens up a significant chunk of the iOS API to ActionScript 3 developers. There’s support for all kinds of things include GameKit, iCloud, Core Image, NewsStand, PassKit, iAD, Social, and In-App Purchase. I’ve been informed by the guys at AIR Extensions that they’ve opened up 2000 native iOS SDK APIs spanning over 300 classes. That’s pretty impressive coverage.