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.
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.