Sleep Cycle - Bio-alarm clock that wakes you up at optimal times based on your sleep patterns.
Alarm Clock Xtreme - Alarm Clock Xtreme: Alarm, Stopwatch, Timer (Free) is the most popular alarm clock app created and published by AVG Labs for both iOS and Android devices.
SleepBot - SleepBot is a sleep tracking app available in Google Play and the Apple App Store.
Awaken - Wake up to Awaken playing your favorite music.
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.
Song Alarm - song-alarm - Simple alarm clock for Android that plays a selected song at a desired time.