Thats a pretty nice app with great potential because its organised on an extremely simple basis. Theres just one logical problem with it - in category view, green tasks come before blue ones, which is weird when you think about green for not important and not urgent, and blue for not important but urgent. One would think they should be ordered in the opposite way?
But in general, its pretty awesome, helps to stay organised fast and efficiently.
skrzacik about Do Matrix : To-do app with time management matrix style, v2.0