Free Alarm Clock - Free Alarm Clock is a free, full-featured and user-friendly computer alarm clock for Windows.
Galarm - Social alarm clock and reminders
Talalarmo - Minimalistic android alarm
Alarmy - World's most annoying alarm app
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.
Digital Clock 4 - Beautiful customizable clock with plugins