Name: PomoDoneApp
Homepage: https://pomodoneapp.com

PomoDone is a performance boosting tool, which uses Pomodoro technique® and works on the top of you current task management service. As a result you don’t need to re-create your list from scratch, just use it for tasks you already have. Moreover it works as a time tracker as well, so you don’t need any additional time tracking system eating your CPU and your attention.

Opensource: No

Tarball: https://app.pomodoneapp.com/Linux64.tar.gz
Deb file: https://app.pomodoneapp.com/PomoDoneApp-1.5.856.deb

They offer a free tier that comes with 3 external service integrations and a paid tier that offers more external service integrations and more options. I didn't see any pomodoro applications in the Software Center, apologies if I missed any.