Galarm - Social alarm clock and reminders

Sleep Cycle - Bio-alarm clock that wakes you up at optimal times based on your sleep patterns.

Alarmy - World's most annoying alarm app

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.

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.

Talalarmo - Minimalistic android alarm