Privacy Policy
Last updated: September 16, 2026
Twiros built the Nihongo Renshuu app as a Free app. This SERVICE is provided by Twiros at no cost and is intended for use as is. We are committed to protecting your privacy and ensuring you have a transparent, safe learning experience.
1. No Account Required & Minimal Data Collection
Nihongo Renshuu is designed with a privacy-first approach. You can use all features of the application without creating an account, logging in, or providing any personally identifiable information (such as your name, email address, physical address, or phone number).
2. Local Data & Learning Progress
To provide you with personalized learning statistics, spaced repetition (SRS) scheduling, and quiz history, the app stores your practice progress. All of this learning data is stored strictly locally on your device (using encrypted and secure local storage). It is never transmitted, synced, or uploaded to our servers or any third parties.
3. Crash Reporting & Diagnostics
To ensure app reliability and resolve technical issues quickly, the app uses third-party diagnostic services (specifically Firebase Crashlytics). When the app encounters an unexpected error or crash, non-personally identifiable technical diagnostic logs may be collected automatically.
This diagnostic data may include:
- Device model, operating system, and architecture
- App version and build number
- Timestamp of the incident and stack traces showing where the error occurred
This data is used solely to fix bugs, optimize performance, and improve stability for all users. It is not linked to your identity or learning records.
Third-party service privacy policies:
4. No Tracking & No Third-Party Advertising
We respect your digital privacy:
- We do not display third-party advertisements.
- We do not track you across other companies' apps or websites.
- We do not collect or access advertising identifiers (such as Apple's IDFA or Google Advertising ID).
- We never sell, rent, or monetize your personal or usage data.
5. User Control and Data Deletion
You have complete control over your learning data at all times:
- In-App Reset: You can permanently erase all stored statistics, SRS review intervals, and quiz history at any time using the Reset Progress option located in the app's Settings screen.
- App Removal: Deleting or uninstalling the app from your device automatically purges all locally stored data and cached files completely.
6. Children’s Privacy
Our Service does not address anyone under the age of 13. We do not knowingly collect personally identifiable information from children under 13. Since no personal information is collected by the application, parents and guardians can feel confident in their children's privacy while studying Japanese vocabulary and grammar.
7. Changes to This Privacy Policy
We may update our Privacy Policy from time to time to reflect improvements or regulatory changes. Any updates will be posted on this page with an updated revision date.
8. Contact Us
If you have any questions or suggestions regarding this Privacy Policy, please feel free to reach out to us at support@twiros.com.