Firaxis has added asynchronous multiplayer to the iOS version of XCOM: Enemy Unknown.

The latest update for the App Store release introduces the new multiplayer mode alongside other tweaks, allowing players to engage in multiplayer battles even when the other player is offline.

The update also adds multiplayer leaderboards and optimisations for iOS7.

XCOM: Enemy Unknown released on iOS earlier this year following its launch on PC, Xbox 360 and PlayStation 3 in late 2012.

The game is currently half price on the App Store, reduced from £13.99 to £6.99 for a limited time.