Privacy Policy

Last updated: March 14, 2026

Viktor Ralchenko ("we", "us", or "our") operates the Deutsch Lernen mobile application (the "App"). This Privacy Policy explains how we collect, use, and protect your information when you use our App.

1. Information We Collect

1.1 Data Stored Locally on Your Device

The App stores the following data locally on your device only:

• Learning progress — vocabulary review history, flashcard ratings, grammar exercise scores, streaks, and study time
• User preferences — selected CEFR level, daily goal, TTS speed, dark mode setting, and interface language
• Chat history — conversations with the AI tutor

This data is not transmitted to our servers and remains on your device. Uninstalling the App will delete all locally stored data.

1.2 Data Shared with Third Parties

• AI Chat Messages: When you use the AI German Tutor (Chat) feature, your messages are sent to Groq API (groq.com) for processing. Groq's privacy policy applies to this data. No personal identifiers are included in these requests.
• Subscription Data: If you subscribe to Premium, payment processing is handled entirely by Google Play. We do not collect, store, or have access to your payment information.

1.3 Data We Do NOT Collect

We do not collect:

• Personal information (name, email, address, phone number)
• Location data
• Device identifiers or advertising IDs
• Analytics or tracking data
• Contacts, photos, or files
• Payment or financial information

2. How We Use Information

All learning data is used solely to:

• Track your study progress and streaks
• Schedule flashcard reviews using the FSRS spaced repetition algorithm
• Adapt AI tutor responses to your CEFR level
• Display statistics and weak areas

3. Third-Party Services

The App uses the following third-party services:

• Groq API (groq.com) — for AI chat functionality. Only chat messages and your selected CEFR level are sent. See Groq's Privacy Policy.
• Google Play Billing — for subscription management. See Google's Privacy Policy.
• Android Text-to-Speech — built-in system service for word pronunciation. No data is sent externally.

4. Data Security

All data is stored locally on your device using Android's standard storage mechanisms. Network communications with the Groq API use HTTPS encryption. We do not operate any servers that store your data.

5. Children's Privacy

The App is not directed at children under 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 personal information, please contact us.

6. Data Deletion

Since all data is stored locally on your device, you can delete all App data at any time by:

• Uninstalling the App, or
• Clearing the App's data in Android Settings > Apps > Deutsch Lernen > Storage > Clear Data

7. Subscriptions

The App offers optional Premium subscriptions (monthly and yearly) through Google Play. Subscription management, billing, and cancellation are handled by Google Play. You can manage your subscription in Google Play Store > Subscriptions.

8. Changes to This Policy

We may update this Privacy Policy from time to time. Changes will be reflected in the "Last updated" date above. Continued use of the App after changes constitutes acceptance of the updated policy.

9. Contact Us

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

Email: vralchenko@gmail.com

Developer: Viktor Ralchenko