LangBook

Build your Japanese writing habit, one sentence at a time.

This app helps you practice Japanese through daily journaling, AI feedback, vocabulary review, and flashcards.
Write about your feelings, your day, or a guided topic, then receive feedback on grammar, vocabulary, expression, and natural flow.

It is designed for learners who want to write more Japanese, build confidence, and make Japanese study part of their daily routine.

■ Japanese journal
Write freely about your day or choose a guided topic when you are not sure what to write.
Start small with just one sentence a day.

■ AI feedback
Get clear feedback on grammar, vocabulary, expression, and natural flow.
The AI helps you make your Japanese sound more natural and easier to understand.

■ Track your progress
See your score, study streak, learning time, and skill balance.
Visual progress helps you stay motivated.

■ Vocabulary and flashcards
Save important words and review them with flashcards.
Practice forgotten words and turn them into usable vocabulary.

■ Recommended for:
・Learners who want to write a Japanese diary
・Students who want to improve Japanese writing
・People looking for AI Japanese correction
・Learners who want to practice Japanese grammar and vocabulary
・Anyone who wants to study Japanese every day
・Students who want to review words with flashcards

One sentence a day can become tomorrow’s confidence.
Start writing in Japanese today.

Some AI features require a subscription.
Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Privacy Policy: https://privacyenglsih.bridra.net