1. Service Description

Duoler is an app for learning languages with your own videos. It provides the following features:

• Import your own videos and subtitle files (SRT, VTT, ASS/SSA) to watch and study
• Generate subtitles for your videos with on-device AI, including bilingual subtitles
• Tap words or sentences in subtitles to see translations
• Save words and sentences to your notebook together with the video clip
• Edit and export subtitles

2. Free Plan & Premium Subscription

2.1 What Each Plan Includes

Feature	Free	Premium
Play videos with your own subtitle files, tap words to translate	✓	✓
Notebook	Unlimited	Unlimited
AI subtitles, including bilingual subtitles	5 minutes per day, 5 minutes per video	Unlimited
Export subtitle files you imported	✓	✓
Export AI-generated subtitles	—	✓

2.2 Premium Subscription

Premium is available as monthly and annual auto-renewable subscriptions. Prices are shown in your local currency on the purchase screen in the app.

2.3 Subscription Terms

• Payment is charged to your Apple Account when you confirm the purchase
• Your subscription renews automatically unless auto-renew is turned off at least 24 hours before the end of the current period. Your account is charged for renewal within 24 hours before the end of the current period
• You can manage or cancel your subscription at any time in Settings > [your name] > Subscriptions
• After cancellation, you can keep using Premium until the end of the current subscription period
• If a free trial is offered, its length and the price after the trial are shown before you subscribe. Unless you cancel at least 24 hours before the trial ends, it converts to a paid subscription
• Any unused portion of a free trial (if offered) is forfeited when you purchase a subscription
• Refunds are handled by Apple under its policies

3. User Content

3.1 Your Content

Videos, subtitles, and other content you import into Duoler remain your property. You must ensure that:

• You own or have the right to use the content you import
• Your content does not infringe any third-party intellectual property or other rights
• Your content does not contain illegal, harmful, or offensive material

3.2 Data Ownership

Learning data you create in Duoler (such as word collections, notes, etc.) belongs entirely to you.

4. Usage Guidelines

When using Duoler, you agree not to:

• Violate any applicable laws or regulations
• Infringe on others' intellectual property or privacy rights
• Attempt to reverse engineer, crack, or modify the application
• Circumvent the app's technical protection measures or feature limitations
• Use the app for any commercial purposes (unless with our written permission)
• Interfere with or disrupt the normal operation of the app in any way

5. Intellectual Property

Duoler and all its content (including but not limited to software code, interface design, icons, text, features) are protected by intellectual property laws. Without our written permission, you may not:

• Copy, modify, or distribute any part of the application
• Use our trademarks, logos, or other brand elements
• Create derivative works based on this application

6. AI Subtitles & Translations

AI subtitles and translations are generated automatically and may contain errors or omissions. They are provided as a learning aid.

7. Disclaimer

• Duoler is provided "as is," and we make no express or implied warranties regarding the completeness, accuracy, or reliability of the application
• AI subtitles and translations are for reference only and may contain errors or omissions
• We are not responsible for any direct or indirect damages resulting from the use of this application
• We are not responsible for any content imported by users

8. Limitation of Liability

To the maximum extent permitted by law, Duoler and its developers shall not be liable under any circumstances for:

• Any indirect, incidental, special, consequential, or punitive damages
• Loss or corruption of data
• Loss of profits or business
• Damages caused by third-party content or services

9. Service Changes & Termination

• We reserve the right to modify, suspend, or terminate the service at any time without notice
• If we believe you have violated these terms, we may limit or terminate your access to the service
• After service termination, you can still access local data on your device

10. Changes to Terms

We may update these Terms of Use from time to time. Updated terms will be posted within the app or on our website. Continued use of Duoler indicates your acceptance of the updated terms.

11. Governing Law

These Terms of Use shall be governed by and construed in accordance with the laws of the People's Republic of China. Any disputes arising from these terms should first be resolved through friendly negotiation; if negotiation fails, either party may file a lawsuit with a court of competent jurisdiction.

12. Contact Us