The Pomodoro technique is efficient for tasks you find boring, but having to take a break when you are 100% concentrated in something you like might be annoying. That's why the Flowtime technique exists: take appropriate breaks without losing your flow.
Instead of strict work and break times, you work as long as you wish and your break is a portion of how long you worked (by default, 20%). For example, if you work for an hour, your break is 12 minutes. This lets you concentrate on your work and take appropriate breaks when convenient without a rigid schedule.
Flowtime v6.1 has arrived with a couple of minor fixes and improvements