AppZapper is one of my favourite OS X apps – I love the name, concept and icon. The latest release adds a “Hit List” app browser, and “My Apps”, a place for keeping license information.
Certainly worth taking a look at as a way to take control of your application clutter.
This page of their site displays a wonderful graphic to explain specific areas of the interface (very similar to that used by Things). Every app should have one of these on their website.