Winterboard - Give your iPhone or iPod Touch a graphical overhaul!
Cydia - An alternative app store for jailbroken devices.
Cylinder - Sexy homescreen icon animations
Zestia - Zestia is a mobile app designed to assist you in organizing your hectic schedule, social life, and professional persona.
Five Icon Dock - Tweaks the dock of your jailbroken iPhone so that it can fit five icons instead of four.
JazzMyApp - Let JazzMyApp surprise you with amazing apps everyday. Try it out yourself.