Gnome Clocks - Clock application designed for GNOME 3
Clock Tab - Clock tab allows you to view the time right in your web browser!
Digital Clock 4 - Beautiful customizable clock with plugins
Clock + - Alarm clock, timer, and stopwatch application for Android
AlarmDJ - Online Alarm Clock - Use YouTube videos or MP3 files as alarm sound. Works offline.
Free Vector Clocks - Free Vector Graphics Desktop Alarm Clocks.