Sleep Cycle - Bio-alarm clock that wakes you up at optimal times based on your sleep patterns.
T-Clock Redux - T-Clock Redux in an enhanced fork of Stoic Joker's T-Clock 2010 with ISO week number support...
SleepBot - SleepBot is a sleep tracking app available in Google Play and the Apple App Store.
DS Clock - Keep your time synchronized with Atomic Time servers, using customizable digital desktop clock with westminster chimes.
Talalarmo - Minimalistic android alarm
AlarmDJ - Online Alarm Clock - Use YouTube videos or MP3 files as alarm sound. Works offline.