Privacy Policy

Last updated: March 7, 2026

Kanjijo ("we", "our", or "us") is committed to protecting and respecting your privacy. This Privacy Policy explains how we collect, use, disclose, and safeguard your information when you use the Kanjijo mobile application ("App") and website at kanjijo.com ("Website").

Please read this privacy policy carefully. By using the App or Website, you agree to the collection and use of information in accordance with this policy.

1. Information We Collect

1.1 Information You Provide to Us

  • Account Information: When you create an account, we collect your email address and display name.
  • Learning Data: Your study progress, review history, SRS level data, and learning statistics.
  • Support Requests: When you contact support, we collect the information you provide in your message.
  • Payment Information: Subscription and purchase information is processed by Apple's App Store. We do not directly collect or store your payment card details.

1.2 Information Collected Automatically

  • Device Information: Device type, operating system version, and unique device identifiers.
  • Usage Data: App usage patterns, features accessed, session duration, and crash reports.
  • Log Data: IP address, access times, and referring URLs when you visit our Website.

1.3 Information from Third-Party Services

  • Firebase Authentication: When you sign in, Firebase may collect authentication tokens and session information.
  • Firebase Analytics: Anonymous usage statistics to help us improve the App.
  • Firebase Crashlytics: Crash reports to help us fix bugs and improve stability.

2. How We Use Your Information

We use the collected information for the following purposes:

  • To provide and maintain the App: Including syncing your learning progress across devices.
  • To personalize your experience: Adapting the SRS algorithm to your learning pace.
  • To improve our services: Analyzing usage patterns to enhance features and fix issues.
  • To communicate with you: Sending important updates, security alerts, and support responses.
  • To process transactions: Managing subscriptions and in-app purchases through the App Store.
  • To ensure security: Detecting and preventing fraud, abuse, and unauthorized access.

3. Data Storage and Security

Your learning data is stored in two locations:

  • Local Storage: All learning data is stored locally on your device using encrypted Hive database (AES-256 encryption).
  • Cloud Storage: If you enable cloud sync (Premium feature), your data is encrypted and stored on Google Firebase servers located in the United States.

We implement industry-standard security measures including:

  • AES-256 encryption for local data storage
  • TLS/SSL encryption for data in transit
  • Firebase Security Rules to restrict unauthorized access
  • Regular security audits and updates

4. Data Sharing and Disclosure

We do not sell, trade, or rent your personal information to third parties. We may share your information only in the following circumstances:

  • Service Providers: We use Firebase (Google) for authentication, database, and analytics services. Google's privacy policy applies to their processing of your data.
  • Legal Requirements: We may disclose your information if required by law, regulation, or legal process.
  • Safety: To protect the rights, property, or safety of Kanjijo, our users, or others.

5. Your Rights and Choices

You have the following rights regarding your data:

  • Access: You can view all your learning data within the App.
  • Correction: You can update your account information at any time.
  • Deletion: You can request deletion of your account and all associated data through the App settings or by emailing support@kanjijo.com.
  • Data Portability: You can request a copy of your data in a machine-readable format.
  • Opt-Out: You can disable analytics in the App settings.

6. Children's Privacy

Our App is not directed to children under the age of 13. We do not knowingly collect personal information from children under 13. If you are a parent or guardian and believe your child has provided us with personal information, please contact us at privacy@kanjijo.com, and we will take steps to delete such information.

7. International Data Transfers

Your information may be transferred to and processed in countries other than your country of residence, including the United States (where Firebase servers are located). These countries may have different data protection laws. By using our App, you consent to such transfers.

8. Data Retention

We retain your personal data for as long as your account is active or as needed to provide you services. When you delete your account, we will delete or anonymize your personal data within 30 days, except where required by law to retain it longer.

9. Third-Party Links

Our App and Website may contain links to third-party websites or services. We are not responsible for the privacy practices of these third parties. We encourage you to review their privacy policies.

10. Changes to This Privacy Policy

We may update this Privacy Policy from time to time. We will notify you of any changes by posting the new Privacy Policy on this page and updating the "Last updated" date. For significant changes, we may also send a notification through the App.

11. Contact Us

If you have any questions about this Privacy Policy, please contact us: