Ô Ăn Quan, or simply known as "food box office" or "agency," is a traditional game played by Vietnamese children. It is a tactical game for two or three players, and can be played with a variety of materials that are easy to obtain. The game involves a rectangular table with ten square boxes on each side, and two semicircle or arc-shaped boxes on the shorter sides. Players take turns moving their pieces, which can be stones, bricks, seeds, or plastic, from box to box, with the goal of capturing their opponent's pieces. The game ends when all the pieces in a box are eaten or there are no more pieces left to distribute.

Now, this classic game has been turned into a mobile app by developer Zegome. The app features the traditional gameplay of Ô Ăn Quan, but with added features such as different difficulty levels, achievements, and a leaderboard to compete with friends and other players. The app is free to download and play, and is available on the Android platform. If you're a fan of traditional games or just looking for a new puzzle game to try, Ô Ăn Quan is definitely worth checking out.