Legal
Privacy Policy
1. Who we are
Mojiru is a Japanese language-learning app developed by Rokku Studio and published on the Apple App Store. If you have questions about this policy, contact us at info@mojiru.app.
2. What Mojiru does not collect
Without an account, Mojiru collects nothing. Even with an account, we never collect:
- Usage analytics, crash reports, or telemetry
- Device identifiers or advertising IDs — Mojiru has no ads
- Location data
- Voice recordings or speech recognition results
3. Data stored on your device
Mojiru stores all study progress, SRS review history, settings, and statistics locally on your device using SQLite and AsyncStorage. This data never leaves your device unless you sign in and enable cloud sync (see Section 4).
You can delete all app data at any time by deleting Mojiru from your device.
4. Optional account and cloud sync
Mojiru offers optional sign-in via Apple Sign In or Google Sign In. Creating an account is not required to use the app — it exists solely to back up and restore your progress if you switch devices.
When you sign in:
- Your email address is stored by Supabase (our authentication provider) to identify your account
- Your study progress, SRS history, bookmarks, and settings are synced to our cloud database
- All data is encrypted in transit (HTTPS) and at rest
- No voice recordings, device data, or personal information beyond your email are collected
You can sign out at any time from Settings → Account. You can permanently delete your account and all synced cloud data from Settings → Account → Delete account in the app; you may also email info@mojiru.app. Supabase is a US-based service — see their privacy policy at supabase.com/privacy.
5. Microphone and speech recognition
The pronunciation practice feature uses your device's microphone and Apple's on-device speech recognition. Mojiru requests permission only when you use this feature.
- Speech recognition runs on-device using Apple's framework — no audio leaves your device
- No recordings are stored by Mojiru or transmitted anywhere
- You can disable microphone access at any time in iOS Settings → Mojiru
6. Subscriptions (Mojiru Pro)
Mojiru offers an optional Pro subscription via Apple's in-app purchase system, managed by RevenueCat. When you purchase a subscription:
- RevenueCat receives your Apple purchase receipt to validate your subscription status
- No personal information beyond the purchase receipt is shared with RevenueCat
- Subscription management is handled entirely by Apple — see your Apple ID settings to cancel
See RevenueCat's privacy policy at revenuecat.com/privacy.
7. Third-party libraries
Mojiru uses the following third-party services. None collect personal data on our behalf beyond what is described above:
- Supabase — authentication and cloud sync (when signed in). Privacy policy
- RevenueCat — subscription management (Pro only). Privacy policy
- Expo / React Native — open-source app framework. No data collection.
- expo-speech / expo-speech-recognition — wraps Apple's on-device TTS and speech recognition APIs.
8. Children's privacy
Mojiru does not target children under 13 and does not knowingly collect personal information from them. The app contains no advertising or behavioural profiling. In-app purchases (Mojiru Pro) are managed by Apple and require an Apple ID.
9. Changes to this policy
If this policy changes, the updated version will be published at this URL with a new effective date. Significant changes will be noted in the app's release notes.