XNote Stopwatch - Try the most feature-rich stopwatch and timer software on the net for free!
Thyme - The task timer for OS X.
Stopwatch - A Java countdown timer and stopwatch. Features a fullscreen and a resizable window mode.
TimeLeft - TimeLeft is a versatile desktop utility - it can be used as a countdown clock, reminder, clock...
SnapTimer - SnapTimer is a simple, free, portable countdown timer for Windows.
wnr - Better than pomodoro, this timer app balances work and rest.