There is an app... well, at the moment there are many great tools for tweaking your Ubuntu. While we develop the ultimate Power Users Tool, take a look at these links.
Ubuntu Tweak - an application designed to make configuration of Ubuntu easier for everyone. It provides many useful desktop and system options that the default desktop environment doesn't provide. http://ubuntu-tweak.com/
Gunity provides easily-accessible options for tweaking aspects of the Unity interface. You can find out more about it on OMG! Ubuntu!
Confity is a similar tool to Gunity but provides even more options to tweak Unity. Project page: sourceforge.net/projects/confity/.
Quicklist Editor for Unity Launcher lets you create Quicklists easily. Project page: launchpad.net/unity-launcher-editor
CompizConfig Settings Manager is a great tool to tweak Compiz and Unity to your needs. Just head to the Ubuntu Software Center, search for CompizConfig Settings Manager and install it. Warning! CompizConfig Settings Manager offers millions of options, some of them might break your user interface! You have been warned, be careful!
Extend your Unity interface with useful Indicators, access commonly used tasks for a specific application quickly with Quicklists or search the entire universe (well, not actually the entire universe, but many interesting sources) with Unity lenses.