Based on the personas of Junping and [TODO] Tina, we would like to implement the following features:

1. Quick and easy to launch and use
2. Ability to define words without retyping them
3. Explanation of words in context with clear and easily understood definitions
4. Capability to explain the content in the viewfinder
5. Automatic pronunciation of words in the selected accent (British/American)
6. Support for multiple languages, including English, German, French, Spanish, Italian, Chinese, Japanese, and Korean
7. Capability to segment words in Chinese, Japanese, and Korean
8. Ability to save words and explanations for exporting to other apps for further review
9. Option to select the language for explanations
10. Ability to define explanation rules, such as generating example sentences and providing explanations in the mother tongue.

However, to build the MVP of the product, we would only build these features at first:

1. Quick and easy to launch and use
2. Ability to define words without retyping them
3. Explanation of words in context with clear and easily understood definitions
4. Capability to explain the content in the viewfinder
5. Automatic pronunciation of words in the selected accent (British/American)
6. Support for multiple languages, including English, German, French, Spanish, Italian, Chinese, Japanese, and Korean
7. Capability to segment words in Chinese, Japanese, and Korean
8. Ability to save words and explanations for exporting to other apps for further review