Top apps for the Apple iPhone and Apple iPad in 2012 were led by games
The top free app for the Apple iPhone was Google's YouTube app which replaced the one that was removed in iOS 6 by Apple. On the tablet side, the number one free app was Skype, which makes sense since it would give Apple iPad users telephone functionality. The top paid app was the same for both the Apple iPhone and the Apple iPad, Angry Birds Space.
source: iTunes via BGR