Things to Try - Pomorodo Technique

I heard about the Pomodoro technique two years ago (when I just joined my previous startup and the schedule was quite crazy) and tried it a few times. I liked it, but I also found that without a real timer it was hard to keep track of things. Fortunately I now find there is an excellent Mac app ($4.99 only, free if you download and build from the source) for it so I am eager to give it a try again. It will also be interesting to see how well it works with the Scrum process. I wonder that after using it whether I will be able to estimate tasks more accurately.