Free Alarm Clock - Free Alarm Clock is a free, full-featured and user-friendly computer alarm clock for Windows.
Memo to Me - Online email & SMS reminder service.
Gnome Clocks - Clock application designed for GNOME 3
Date Reminder - Date Reminder reminds you of recurring or nonrecurring events, like birthdays, bills to pay...
AlarmDJ - Online Alarm Clock - Use YouTube videos or MP3 files as alarm sound. Works offline.
Digital Clock 4 - Beautiful customizable clock with plugins