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
SleepBot - SleepBot is a sleep tracking app available in Google Play and the Apple App Store.
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