Alarmy - World's most annoying alarm app
Winterboard - Give your iPhone or iPod Touch a graphical overhaul!
Galarm - Social alarm clock and reminders
Dreamboard - DreamBoard lets you take control over the homescreen of your jailbroken iPhone.
Free Alarm Clock - Free Alarm Clock is a free, full-featured and user-friendly computer alarm clock for Windows.
Springtomize - Tear down the walls