Like most mobile games developers, we’ve been closely following what important additions and changes the recently released iOS 7 update has made. One of the biggest and most exciting of Apple’s initiatives is the standardization of game controllers for iOS-based platforms. So we’re happy to tell you that, in addition to several important bug fixes for Xcode 5 / iOS 7 (Build&Run, WebCamTexture and status bar), Apple Controller support is included with 4.2.2!First introduced with iOS 7, Apple’s Game Controller API is designed to work with MFi (Made for iPhone) game controllers. While no such controllers have yet to be released, several are said to be in the works, including offerings from Logitech and GameCase.
Multiple games have also begun incorporating Game Controller support, including major titles like Walking Dead and Bastion. Though there is no information available on when MFi controllers might be available, increasing news of support suggests that the release could come at any time, possibly during Apple’s iPad-centric fall event.
Unity's blog post also has a mini tutorial for Unity developers that includes tips on how to add controller support to games.