Google Play game services, the backend that powers online features for many Android games, is expanding significantly to iOS. In an announcement timed for the Game Developers Conference this week, Google says it’s bringing turn-based and real-time multiplayer capabilities to iOS. Should developers choose to integrate the service with their games, they’ll be able to enable gamers with Android and iOS devices to play against each other cross-platform. Play Games already supports iOS through a plug-in for the Unity game engine that supports achievements and leaderboards, and that plug-in will be updated soon adding the multiplayer element. An early version of a separate SDK for non-Unity games is also being released, but at launch it won’t support multiplayer gaming. As we exclusively revealed recently, Microsoft is planning to expand Xbox Live to mobile platforms in order to facilitate multiplayer matchmaking, achievements, and friends lists.