1. Service Description

Duoler is a video-based language learning application that provides the following features:

• Import video and subtitle files for learning
• Tap on subtitles to view word definitions
• Collect vocabulary and manage your word collection
• Export word collection to Anki, CSV, or JSON formats
• Offline dictionary lookup service

2. User Account & Subscription

2.1 Free Version Limitations

Duoler offers a free version with the following limitations:

Feature	Free Version Limit
Total Word Lookups	50 unique words
Word Collection Capacity	20 words
Data Export	Not available

2.2 Premium Subscription

Subscribe to Duoler Premium to unlock all features, including:

• Unlimited word lookups
• Unlimited word collection capacity
• Data export functionality (Anki, CSV, JSON)

Subscription options:

• Monthly Subscription: $2.99/month
• Annual Subscription: $19.99/year (save approximately 42%)

2.3 Subscription Terms

• Subscription fees will be charged to your iTunes account
• Subscriptions automatically renew within 24 hours before the end of the current period, and your account will be charged accordingly
• You can manage or cancel your subscription at any time in iOS Settings > Apple ID > Subscriptions
• After cancellation, you can continue using premium features until the end of the current subscription period
• Any unused portion of a free trial period (if offered) will be forfeited upon purchasing a subscription

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. You can export this data at any time.

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. Dictionary Data

The ECDICT dictionary data used by Duoler is available under public domain/open source license. Dictionary data is for personal learning use only.

7. Disclaimer

• Duoler is provided "as is," and we make no express or implied warranties regarding the completeness, accuracy, or reliability of the application
• Dictionary definitions 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