WorkFlowy is ingenious . It is so simple, yet so effective. If I were to describe it to you, you might have a hard time appreciating why I am making all the fuss. But trust me, to use it is to love it.
I love it for a number of reasons.
1) It simplifies my todo lists into one massive yet easy to organize list.
2) It is a great way to keep a running log of what you accomplished.
3) It is possible to have a massive list that is still easy to focus on.
4) The ease of the tool allows you to focus on what you are trying to do / think about and not have to fuss with focusing on the tool.
If you like to or want to get or stay organized and simplify your life, check it out.