iOS 7 Included a neat little feature: API support for game controllers. This means that developers can create standardized controllers that aren't tied down to one game manufacturer.
The MOGA ACE controller is the first of its kind to make use of Apple's new API to enable more engaging and precise gaming on 5th generation non-iPad iOS devices.
Unfortunately, the MOGA has been critically reviewed as a great device concept with lots of potential, but poorly executed. Some problems arise not from the hardware itself, but from games not being fully optimized to work with the controller API. Dead Trigger 2 is an example, where the default sensitivity settings are set astronomically high.
Hit the link for the full review by TouchArcade.