Judo Reference is a free Android app developed by RdyDev that provides an extensive guide to Judo techniques. The app allows you to browse and search through techniques such as ne-waza, tachi-waza, shime-waza, and kansetsu-waza. The techniques are presented with frame-by-frame animations, which makes them easy to understand. You can also star techniques for quick access before training.

The app also offers a multiple-choice test based on your grade to test yourself and improve your knowledge of Judo. Additionally, the app suggests techniques just before your training sessions, making it an excellent tool to prepare for your next session. Judo Reference also enables you to look up terminology and find videos on Youtube.

Overall, Judo Reference is an excellent app for anyone looking to improve their knowledge of Judo techniques and terminology. The recent update added a filter test by grade feature, which was requested by one of the users. If you have any suggestions, the developer encourages you to email them.