Free Alarm Clock - Free Alarm Clock is a free, full-featured and user-friendly computer alarm clock for Windows.
Sleep Cycle - Bio-alarm clock that wakes you up at optimal times based on your sleep patterns.
Digital Clock 4 - Beautiful customizable clock with plugins
SleepBot - SleepBot is a sleep tracking app available in Google Play and the Apple App Store.
G'Morning - Alarm Clock - When your alarm goes off, you will be asked to solve a simple multiplication question in order to turn the alarm off. The alarm will keep ringing until you answer correctly. Have a wonderful G’Morning!
Online Alarm Clock - The world's original online alarm clock, established in 2006.