There is no app for that but if you want to change the UI you can do it with a custom rom like core Droid and bullet proof custom Roms. Ive no experience with it myself but I do know a couple of people who got both up and running and it worked well for them. But if you dont know what you are doing it could brick your phone or otherwise do damange to it. So this isn´t for the faint of heart.
Check our the root forum
if you want more info on rooting or installing a custom rom.