21 MASTER is a free Android card game developed by BAN QIANG. The game challenges you to get as close to 21 as possible without going bust. If you've never played Blackjack before, it's easy to learn. Simply place your bet and receive two cards. Picture cards are worth 10 points, while Aces are worth either 1 or 10.

The game features random dealing, with cards dealt from up to 8 decks. As you play, you'll increase your level and improve your skills, learning how to outwit the dealer. There's no need to register, simply download the game and start playing. The game is also customizable, allowing you to play with your own rules, decks, and tables.