Tasker is on sale for a limited time. It's recently been updated and it now has a Holo theme. It's normally 6.49 so this is a pretty good deal.
For those that don't know, Tasker is an automation app. You can have it do things based on contexts. The range of things it can do is basically limitless. You can set it up to do things based on your location, state of your phone, what your schedule is. It also has plugins that add even more features. There's a basic FAQ and wiki that is linked with it.