Great :) I am almost able to substitute Pomodroido with this.
Some very easy improvements:
1) Bigger font (or ability to set size), as I have the clocks on a secondary screen far from the working screen. I would run it at 40px or so :D
2) Sound/Beep in Linux is not working, but anyway a popup window would be much better so that we don't depend on remember to un-mute the volume or raise it.
Although in ThinkingRock I have my "Time" categories in pomodoros (1 pmd / 2 pmd / 5 pmd ...), I don't need any kind of integration with ThinkingRock at all. But if the whole functionality would be a Thinking Rock plugin running as a toolbar would be good too.