Atcoder Companion Plus by Thể Thao Sodo66

Enhance your experience by providing some useful features designed to streamline your workflow and boost your productivity.

This extension offers some key features:

1. Estimate performance and rating during contests.
2. Add test cases to a problem statement (disabled by default, open the setting popup to enable).
3. Show the status of the problems you have submitted.
4. Allow copying and downloading test cases (each or all) with one click.
5. Simplify debugging with the custom test page.

Blog on Codeforces: https://codeforces.com/blog/entry/133287
Feel free to open an issue or submit a pull request on GitHub: https://github.com/conlacda/atcoder-companion