3. Vainglory
This multiplayer online battle arena (MOBA) gets its inspiration from the likes of League of Legends and DOTA 2. Offering state of the art graphics (for the latest iPhone, anyway) and three-on-three team-based action, Vainglory is the game to get if you’re aching for some online player-versus-player combat. The game is fun, and remarkably enough, it’s also free.