Song Alarm - song-alarm - Simple alarm clock for Android that plays a selected song at a desired time.
SleepBot - SleepBot is a sleep tracking app available in Google Play and the Apple App Store.
Talalarmo - Minimalistic android alarm
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.
Insane Alarm - Wakes you up no matter what! Features - obscenely loud blaring emergency alarm sound.
Sleep Cycle - Bio-alarm clock that wakes you up at optimal times based on your sleep patterns.