OpenKit is an open source, back end as a service for mobile games. OpenKit supports iOS, Android, and Unity games.
With OpenKit, you can quickly add social features to your games to increase engagement and retention.
Use social leaderboards so players can compete against their friends. Social challenges send push notifications to players when their friends beat them, bringing them back into the game. Use cloud storage to sync game state across multiple devices. OpenKit manages user accounts and social sign in, and even works with GameCenter on iOS.