In his own words:
Things 3 is the best task management app out there. It is simple and easy to use, and it has a beautiful design. While being powerful enough for even the most detailed and organized power user, it is also simple enough for the rest of us.
In our new course, All The Things, we will quickly show you how to get up and running with Things 3.
Moreover, you will get additional, in-depth systems for a more calm approach to productivity and easier task management.