Privacy Policy

1. Who we are

Fonvo is an AI-powered language learning app for iOS (Bundle ID: app.fonvo). The data controller responsible for your personal data is:

2. What we collect

Fonvo collects only the data necessary to provide you with a personalized language learning experience. Here is a summary:

• Account information -- email, display name, OAuth provider identifier
• Conversation data -- messages you exchange with AI tutors, including error analyses and translations
• Vocabulary data -- words and phrases extracted from your conversations, along with spaced repetition progress
• Learning preferences -- your chosen language, proficiency level, appearance settings, and AI model preferences
• Streak and progress data -- daily activity tracking for motivation features

3. Authentication

You can sign in to Fonvo using one of the following methods:

• Apple Sign-In
• Google OAuth
• Email and password

Authentication is handled by Supabase Auth. When you sign in, we store your user ID, email address, display name, and OAuth provider identifier. Authentication tokens are securely managed by the Supabase SDK and stored in the iOS Keychain on your device.

We never see or store your Apple or Google account passwords. OAuth flows are handled entirely by the respective providers.

4. Voice and audio data

Fonvo offers voice-based conversation practice. Here is exactly what happens with your audio:

Standard voice mode

• Audio is recorded temporarily on your device (M4A format, 16 kHz, mono)
• The recording is immediately sent to a speech-to-text service for transcription
• The audio file is deleted from your device immediately after transcription
• Only the transcribed text is stored -- we do not keep audio recordings

Realtime voice mode

• Audio is streamed in real time via a secure WebSocket (WSS) connection to OpenAI
• Each session uses a short-lived, single-use ephemeral token
• No audio is stored on our servers or on your device

5. Third-party AI providers

To power conversations, speech recognition, and text-to-speech, Fonvo sends data to the following third-party AI services. Per Apple's App Store guidelines (section 5.1.2(i)), we identify each provider and the data shared with them:

Each of these providers processes your data according to their own privacy policies. We encourage you to review them:

• OpenAI Privacy Policy
• OpenRouter Privacy Policy
• ElevenLabs Privacy Policy

We use API-level access to these services, meaning your data is processed for inference only and is not used to train their models (subject to each provider's API data usage policies).

6. Data stored on your device

Fonvo stores the following data locally on your iPhone:

• Conversations -- messages, error analyses, and translations, saved as JSON files
• Vocabulary -- extracted words and phrases with spaced repetition (SRS) scheduling data
• Preferences -- language, proficiency level, appearance settings, and model choices
• Authentication tokens -- stored in the iOS Keychain

All local files are protected with iOS Complete File Protection (.completeFileProtection), which means they are encrypted and inaccessible when your device is locked.

7. Data synced to our servers

To enable cross-device access and to prevent data loss, the following data is synced to our backend:

• Conversations and messages
• Vocabulary items and SRS progress
• User preferences
• Streak and daily activity data

Sync happens asynchronously in the background. All data is transmitted over HTTPS (TLS encryption in transit). Our backend runs on Railway with a Supabase PostgreSQL database.

8. Analytics

Fonvo logs basic usage events locally on your device using Apple's built-in os.Logger framework. These events include:

• App launched
• Conversation started or ended
• Flashcard review completed
• Vocabulary extracted

These logs stay on your device and are used only for debugging purposes. We do not use any third-party analytics services. No data is sent to Firebase, Amplitude, Mixpanel, or any similar service.

9. Security measures

We take the security of your data seriously. Here are the measures in place:

• API keys are fetched fresh after authentication, held in memory only, and never written to disk
• Keychain storage uses kSecAttrAccessibleWhenUnlockedThisDeviceOnly, meaning credentials are only accessible when your device is unlocked and never backed up to other devices
• All network communication uses HTTPS (TLS) or WSS (secure WebSockets)
• Ephemeral tokens are used for realtime voice sessions -- they are short-lived and valid for a single session only
• Local files are encrypted at rest with iOS Complete File Protection

10. Cross-border data transfers

Your data may be processed in the following locations:

For users in the European Economic Area (EEA), transfers to the United States and other countries outside the EEA are safeguarded by Standard Contractual Clauses (SCCs) or equivalent mechanisms as required by the GDPR.

11. Data retention and deletion

How long we keep your data

Your data is retained for as long as you maintain an active Fonvo account. There is no automatic expiration -- your conversations, vocabulary, and progress remain available until you choose to delete them.

Deleting your account

You can delete your account from within the app (Profile > Settings > Delete Account). When you delete your account:

• All server-side data is permanently deleted via a cascading delete operation
• This includes your profile, conversations, vocabulary, preferences, and streak data
• This action is irreversible

Data stored locally on your device remains until you uninstall the Fonvo app. Uninstalling the app removes all local data.

12. Your rights (GDPR)

If you are located in the European Economic Area, you have the following rights under the General Data Protection Regulation:

• Right of access -- request a copy of the personal data we hold about you
• Right to rectification -- request correction of inaccurate or incomplete data
• Right to erasure -- request deletion of your personal data (also available via in-app account deletion)
• Right to restriction -- request that we limit how we process your data
• Right to data portability -- receive your data in a structured, machine-readable format
• Right to object -- object to certain types of processing
• Right to withdraw consent -- where processing is based on consent, you may withdraw it at any time

To exercise any of these rights, please contact us at contact@fonvo.app. We will respond within 30 days.

You also have the right to lodge a complaint with your local data protection authority. In Poland, the supervisory authority is:

13. Children's privacy

Fonvo is not directed at children under the age of 13. We do not knowingly collect personal data 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 contact@fonvo.app and we will promptly delete the data.

Users between the ages of 13 and 16 (or the applicable age of consent in their jurisdiction) should have a parent or guardian review this privacy policy before using Fonvo.

14. Changes to this policy

We may update this privacy policy from time to time. When we make changes, we will update the "Last updated" date at the top of this page. For significant changes, we will notify you through the app or via email.

We encourage you to review this policy periodically to stay informed about how we protect your data.

15. Contact us

If you have any questions about this privacy policy, your personal data, or want to exercise your rights, please reach out:

We aim to respond to all inquiries within 30 days.