Hourglass - Hourglass is the most advanced simple countdown timer for Windows.
SS Birthday Reminder Live - Improve personal organization and don't forget important things.
SnapTimer - SnapTimer is a simple, free, portable countdown timer for Windows.
Symbyoz Happy Birthdays - A smarter way to keep up with your birthdays.
Free Countdown Timer - Free Countdown Timer is a free, full-featured and user-friendly countdown timer for Windows
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.