Riichi Calc is a useful Android application that helps Japanese Mahjong players determine all possible winning combinations. It is an easy-to-use app that can calculate any valid Japanese Mahjong hand. The app can rearrange the tiles in any order, making it easier for players to determine waits of a tenpai hand. This app is a great companion for any Japanese Mahjong player.

The app provides warnings against illegal combinations, such as riichi with an open hand. Additionally, it can calculate points using han and fu as the input. The displayed terminology is available in English or romanized Japanese. The app is compatible with Android 9.0 and is completely free.

Overall, Riichi Calc is a great tool for Japanese Mahjong players who want to improve their gameplay. The app is simple and easy to use, with no unnecessary features that could confuse the user. If you encounter any calculation errors, you can reach out to the developer via email.