Hourglass - Hourglass is the most advanced simple countdown timer for Windows.
TimeLeft - TimeLeft is a versatile desktop utility - it can be used as a countdown clock, reminder, clock...
Online Alarm Kur - Free online alarm clock, set alarm easily on your computer using the internet alarm clock without downloading any software, wake up in time with the loud online alarm clock.
CountDown Kings Free Countdown Timer - CountDown Kings Free Countdown Timer is a free countdown timer for Mac OS X and Windows operating systems.
TIMEBOX - An advanced timer for professional meeting facilitators
Final Countdown - Final Countdown is a simple countdown timer just like sleeper timer on your TV that will work despite the fact your PC is powered off.