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.
Alarmy - World's most annoying alarm app
Sleepedy - Personal sleep coaching & therapy
Galarm - Social alarm clock and reminders
Pzizz - Sleep at the push of a button! Now with "Focus"
Free Alarm Clock - Free Alarm Clock is a free, full-featured and user-friendly computer alarm clock for Windows.