MahjongBeginner is an Android app developed by Cross Field Inc. and it is free to download. The app is a great tool for beginners to learn how to play Mahjong, one of the most popular board games in the world. The app offers a variety of features that allow users to learn the rules of the game, practice with a CPU, and measure their power of Mahjong.

The app is user-friendly and easy to navigate. Users can learn how to play Mahjong step-by-step with the help of the app's commentary function. The app also offers a practice mode where users can play against a CPU opponent. The app's measurement feature allows users to see how good they are at playing Mahjong. Overall, MahjongBeginner is a great app for anyone who wants to learn how to play Mahjong or improve their skills.