Warner Bros. revealed an iOS variation of NetherRealm's upcoming DC-themed fighting game Injustice: Gods Among Us earlier today at GDC.
Unfortunately, the publisher isn't allowed to share any details at the moment other than it exists. Allegedly the iOS game is due around the same time as the console version of Injustice which is coming to PS3, Xbox 360 and Wii U on 19th April in Europe and 16th April in North America.
This isn't the first mobile fighting game by NetherRealm as it made the iOS Arkham City spin-off Batman: Arkham City Lockdown in 2011. It featured the caped crusader fighting foes one on one.