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.
Alarmy - World's most annoying alarm app
iSleep - iSleep features a sleep timer coupled with an optional Alarm Clock for iTunes and DVD Player.
Online Alarm Clock - The world's original online alarm clock, established in 2006.
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