A free app for Android, by Com2uS.

Homerun Battle 2 is a multiplayer baseball game in which players compete in head-to-head matches. It allows you to customize your player and select a stadium in which to compete. There are six different modes to choose from, and the game allows you to compete in all of them. These modes are duel, survival, mission, burning, arcade, and training.

There are 20  million players worldwide, and they are battling it out in 300 million online matches.

The game is free but you can unlock some extra items through in-app purchases.