cnDB

Privacy Policy

Effective Date: 2025.06.10

App Name: cnDB

Contact: support@cndb.app


1. Who We Are

We ("we", "our", or "us") are the developers of cnDB. This policy explains how we collect, use, and protect your personal data when you use our app, in accordance with the General Data Protection Regulation (GDPR).

2. What Data We Collect and Why

We use Firebase Authentication by Google to manage user logins. Depending on the login method, we may collect the following personal data:

Login Type Data Collected Purpose
Email & Password Email address Authenticate you in the app
Google/Apple Sign-In Email, name, profile picture Authenticate and provide easy access

We do not collect passwords directly — these are handled securely by Firebase.

3. Legal Basis for Processing

Under the GDPR, we rely on the following lawful bases:

  • Consent – when you explicitly sign in or register.
  • Contract – for providing app functionality that depends on authentication.
  • Legitimate Interest – for minimal data used to ensure app security and user access.

4. Data Storage and Transfer

Your data is stored securely by Google Firebase, which may process data on servers located outside the EU, including in the United States.

Google uses Standard Contractual Clauses and other legal mechanisms to ensure GDPR-compliant data protection for international transfers.

More on Firebase's compliance

5. How Long We Keep Your Data

We retain your personal data only as long as necessary for the purpose of providing authentication and maintaining your account.

You may delete your account at any time. Upon deletion, associated personal data is removed from our systems and Firebase Authentication.

6. Your Rights Under GDPR

As an EU/EEA resident, you have the following rights:

  • Access – Request a copy of your personal data.
  • Rectification – Correct any inaccurate data.
  • Erasure – Request deletion of your account and data.
  • Portability – Obtain your data in a usable format.
  • Objection & Restriction – Limit how we use your data in certain cases.

To exercise these rights, contact us at support@cndb.app.

7. How We Protect Your Data

Firebase encrypts all authentication data in transit and at rest.

We use secure APIs and follow industry best practices to protect your data from unauthorized access.

8. Subprocessors

We use Google Firebase as a subprocessor for authentication services.

View their subprocessors

9. Data Saved by Us

Your progress, as well as dictionary data, is stored on your device (browser or mobile device).

Additionally, we save your learning progress, uploaded books, and email address in our database to provide a better user experience.

For social and group features, we also store chat messages and related metadata (such as sender, group, and timestamps) so conversations work across devices and sessions.

If you want your chat messages deleted, you can initiate deletion in the app or by contacting support@cndb.app. We will process verified deletion requests in accordance with applicable law and our operational/legal retention obligations.

10. Payment Processing

We use RevenueCat for payment processing. RevenueCat's privacy policy applies to any payments made through our app.

View RevenueCat's privacy policy

11. Data Sent to External AI Services

We use Google Gemini AI to translate sentences and Microsoft Azure to process generated audio files. These services collect and process data as described in their respective privacy policies.

View Gemini AI's privacy policy

View Microsoft Azure's privacy policy

12. Google Fonts

We use Google Fonts to display text in our app. Fonts are dynamically downloaded across the web. This can therefore send data such as IP addresses to their servers.

View Google Fonts' privacy policy

13. Changes to This Policy

We may update this Privacy Policy. We will notify users via in-app message or email if significant changes are made.

14. Contact Us

For any questions or data requests, contact:

Email: support@cndb.app