Free Alarm Clock - Free Alarm Clock is a free, full-featured and user-friendly computer alarm clock for Windows.
Alarmy - World's most annoying alarm app
Galarm - Social alarm clock and reminders
Wake N Shake Alarm Clock - Wake up with a jolt of energy ready to get shit done.
Digital Clock 4 - Beautiful customizable clock with plugins
Wakefy - Turn your Mac into a Spotify alarm clock.