With the NDA finally lifted, we can finally talk about all of the amazing new APIs in iOS 7. And there are a lot of them. "1500 new APIs", by Apple's count during the WWDC Keynote. (Granted, a good portion of that could just be all of the changes from id to instancetype, but that's a huge number, regardless).Mattt Thompson
Very brief overview about major changes in iOS 7 backstage. Use it as a stating point in new API exploreation.