Japanese Grammar Handbook is an Android app designed by Nahu Studio for learners of Japanese language preparing for the JLPT exam. The app offers a comprehensive guide to Japanese grammar from N5 to N1 levels, along with a dictionary of grammar rules, meaning and examples.

The app provides practice tests to help learners evaluate their understanding of different grammar concepts. It also includes a feature to mark known and unknown grammar rules and add them to favorites for quick access. Learners can choose their level from N5 to N1, depending on their proficiency level. The app also provides audio for sample phrases to help learners with pronunciation and intonation.

One of the unique features of the app is its new study tracking method that helps learners keep track of their progress. The app is free and offers a user-friendly interface, making it easy for learners to navigate and access the grammar rules. Overall, Japanese Grammar Handbook is an excellent resource for learners of Japanese language preparing for the JLPT exam.