Playdead has announced that their hit Limbo will go to iOS on July 3rd. They also happily announced that the game's lifetime sales have been 3 million and growing for the platforms its currently on.
The iOS version will only be supported on the iPad 2 and up, the iPhone 4S and up, the iPad mini, and the latest generation iPod Touch. It will cost $4.99.
Limbo is already on the Vita, but the Vita port does not implement touch controls. This port is the first time the game will have touch controls, something that Playdead said forced them into "rethinking the controls and performing extensive optimizations to ensure an amazing touch-based experience."
[Source]