Galarm - Social alarm clock and reminders
144blocks - Colorful way to track your time! Inspired by Wait But Why
Alarmy - World's most annoying alarm app
Clock mini - Simple clock app in the Dock
Alarm Clock Xtreme - Alarm Clock Xtreme: Alarm, Stopwatch, Timer (Free) is the most popular alarm clock app created and published by AVG Labs for both iOS and Android devices.
Clocks - A minimal world clock app for your Mac's menubar