Privacy Policy
Last updated: February 28, 2026
Kotogoo is developed and operated by Nguyen Quang Trung (individual developer). This policy explains what data we collect, why we collect it, and how we use it when you use our Japanese language learning app and website.
1. Information We Collect
Account Information
When you create an account, we collect:
- Email address
- Display name (chosen by you)
- Authentication data (via Firebase Auth)
- Account creation date and last login
Voice & Audio Data
When you use speech recognition features:
- Your voice is processed in real-time for speech-to-text conversion
- Audio is sent to your device's speech recognition service (Android SpeechRecognizer / iOS Speech framework)
- We do not store or record your voice audio on our servers
Usage Data
- Stories and chapters you have accessed
- Chat history with the AI (stored locally on your device and in your account)
- Language preferences
- Token usage count (to enforce usage limits)
- App version and device type (for troubleshooting)
2. How We Use Your Information
- To provide and improve the Kotogoo learning experience
- To save your progress and sync it across devices
- To send account verification and security emails
- To enforce usage limits per account type
- To respond to support requests
3. Third-Party Services & International Data Transfers
Firebase (Google)
We use Firebase for authentication, database storage, and app hosting. Your data is stored on Google's servers, which may be located outside your country of residence. See Firebase Privacy Policy.
OpenAI / AI Services
Your chat messages are sent to AI services (servers located in the United States) to generate responses. We do not use your conversation data to train AI models.
Google Sign-In
If you sign in with Google, Google shares your name and email with us. See Google Privacy Policy.
Google Play & Apple App Store
When you purchase a Premium subscription, payment is processed by Google Play or Apple App Store. We do not store your payment card details. See their respective privacy policies for details.
By using Kotogoo, you consent to your data being transferred to and processed in countries outside your own, including the United States and Vietnam, in accordance with this Privacy Policy.
4. Advertising
Kotogoo does not display third-party advertisements and does not share your data with advertising networks for marketing purposes.
5. Data Retention
We retain your data as long as your account is active. When you delete your account, we permanently delete:
- Your profile information
- Your story progress
- Your chat history
- Your Firebase Auth account
6. Your Rights
You have the right to:
- Access the data we hold about you
- Request correction of inaccurate data
- Delete your account and all associated data (available in-app under Profile → Delete Account)
- Export your data — contact us at support@kotogoo.com
- EU/EEA users (GDPR): You may object to processing, request data portability, and lodge a complaint with your local data protection authority
- California residents (CCPA): You have the right to know what data we collect, request deletion, and opt out of sale (we do not sell your data)
7. Children's Privacy
Kotogoo is not directed to children under 13. We do not knowingly collect personal information from children under 13. If you believe a child has provided us with personal information, please contact us immediately.
8. Security
We implement industry-standard security measures including encrypted data transmission (HTTPS/TLS), Firebase security rules, and regular security reviews. No method of transmission over the internet is 100% secure, but we strive to protect your data.
9. Changes to This Policy
We may update this Privacy Policy from time to time. We will notify you of significant changes by email or by displaying a notice in the app. Your continued use of Kotogoo after changes constitutes acceptance of the updated policy.