Sega has released a new iOS update of Sonic 2 recently, and it's pretty amazing. This version is essentially the definitive port of the game, with a finished Hidden Palace Zone -- a level that's never been fully playable before.
But strangely, iOS 7 controller support is not listed anywhere on the game's page or the iTunes description. Following up on a tip I received from CNET's Scott Stein, I attached a Powershell and an Ace Power to my device, and found out there's actually hidden iOS controls natively supported. Since Sonic 2 is essentially a one button game anyway, it works perfectly.
Hopefully Sega can get iOS controls up and running for every game on the marketplace.