ClocX - ClocX - freeware analog clock for Windows desktop with many features like calendar, alarms, skins, antialiasing and transparency.
Sleep Cycle - Bio-alarm clock that wakes you up at optimal times based on your sleep patterns.
LClock - Longhorn systray clock program
SleepBot - SleepBot is a sleep tracking app available in Google Play and the Apple App Store.
DS Clock - Keep your time synchronized with Atomic Time servers, using customizable digital desktop clock with westminster chimes.
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.