21 Durak is a free Android card game app developed by Liutauras Stravinskas. It features three classic card games: Durak, 21, and War. Durak is a Russian card game where the goal is to get rid of all cards. 21, also known as Blackjack, is a casino banking game where the player's objective is to beat the dealer by getting 21 points on the first two cards or reaching a higher score without exceeding 21. War, on the other hand, is a simple game where the objective is to win all the cards by having the highest card value.

The app provides a simple and user-friendly interface with easy-to-understand instructions for each game. It is compatible with Android 9.0 and can be played offline. The game also allows players to choose the difficulty level, making it suitable for beginners and advanced players alike. Overall, 21 Durak is a great app for card game enthusiasts who want to play classic games on their mobile devices.