A free program for Android, by Rockbite Games.

Battle Cards: Real-time PVP is a game of skill and chance that lets you build your own card decks to play with. The game is about competing in an arena, where you can fight other players for prizes and become the ultimate champion. You can also chat with other players from around the world, as well as form guilds to compete in friendly games in your own duck quarters. 

Battle Cards is designed to be fun and easy to learn, but difficult to master. There are lots of different characters to collect and use in your card decks, so you can enjoy a wide variety of battles.