1. Information Collection

1.1 Information We Collect

Duoler follows a local-first design philosophy. Most of your data is stored on your device:

• Video and Subtitle Files: Videos and subtitles you import are stored locally on your device. We do not upload or access these files.
• Word Collection Data: Words you collect, definitions, context, and other learning data are stored in the local SwiftData database on your device.
• User Preferences: Settings like language preferences and playback options are stored locally in UserDefaults.
• Usage Statistics: For free users, word lookup counts are stored locally to manage free tier limitations.

1.2 Subscription Information

If you purchase a premium subscription, the transaction is processed through Apple's App Store. We only receive subscription status information from Apple (such as whether you are a subscriber and subscription expiration date). We do not have access to your payment details or personal financial information.

1.3 Dictionary Service

Duoler uses the built-in ECDICT offline dictionary. Word lookups are performed entirely on your device without requiring an internet connection, and we do not send your searched words to any server.

2. Use of Information

The limited information we collect is used only to:

• Provide and improve Duoler's core functionality
• Manage your subscription status
• Maintain free tier feature limitations

3. Information Sharing

We do not sell, trade, or otherwise transfer your personal information to third parties, except:

• Legal Requirements: When required by law or government authorities.
• Service Providers: Apple, as the app distribution and subscription payment provider, processes relevant information according to their privacy policy.

4. Data Export

Duoler allows you to export your word collection data in the following formats:

• Anki Package (.apkg) - Can be directly imported into Anki
• CSV format - Can be opened with Excel or similar software
• JSON format - Structured data format

Export functionality is exclusive to premium subscribers. Exported files are entirely under your control; we do not retain or access your exported data.

5. Data Security

We take the following measures to protect your data:

• All user data is stored locally on your device, protected by iOS system security mechanisms
• The app does not access your files or data in the background
• Subscription verification is performed through Apple's secure StoreKit framework

6. Children's Privacy

Duoler does not knowingly collect personal information from children under 13. If you discover that we have inadvertently collected information from a child, please contact us, and we will delete the relevant data immediately.

7. Your Rights

You have complete control over your data:

• Access and Export: You can view and export your learning data at any time
• Deletion: You can delete any collected words within the app, or delete all local data by uninstalling the app
• Subscription Management: You can manage or cancel your subscription at any time through iOS Settings

8. Third-Party Services

Duoler uses the following third-party services:

• Apple StoreKit: For processing in-app subscription purchases

9. Policy Updates

We may update this Privacy Policy from time to time. Updated policies will be posted within the app or on our website, with the "Last Updated" date revised accordingly. We recommend reviewing this policy periodically to stay informed of any changes.

10. Contact Us