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.
Gnome Clocks - Clock application designed for GNOME 3
Sleep Time - Alarm Clock - Sleep Time provides insight into your sleep patterns. By tracking your level of movement throughout the night, Sleep Time generates customized sleep data in easy-to-read charts.