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.
My Own Clock - Wooden gear clocks, clock kits, and do-it-yourself clock plans. These original all-wood clocks are functional, attractive, and fun!
Sleep as Android - Common alarm clocks ignore your sleep cycles, they wake you on schedule no matter your are currently in your deep sleep. Waking up from deep sleep is unpleasant, it makes you tired and it may negatively affect your productivity during the whole day.