MacPilot Lite allows you to activate some hidden features in OS X. The app lets you easily turn on 150 features that you would have to activate by other means, like the Terminal app or by modifying system files. All of the features that you activate using this app can be just as easily deactivated from within the application, which makes it easy to experiment.
The main window shows a list of categories on the left. These are Finder, Dock, iTunes, Mail, QuickTime X, Safari, Spotlight, System, Miscellaneous, Maintenance and Tools. If you click on any of those, you will see on the right all the new features that you can activate. There are quite a few, so I will just mention the ones I liked the most. I play a lot of multimedia files on my Mac, so I liked that MacPilot Lite lets me configure QuickTime X to automatically start playing movies and to show closed captioning and subtitles when available. In the Dock features, there is one that lets you lock the dock so that no items can be added, moved or removed and so that the size doesn't change. Another interesting feature here is the Single Application Mode, which basically restricts off-focus apps from displaying windows.
In short, there are quite a few interesting things that you can do with MacPilot Lite and it is only $5.