Hourglass - Hourglass is the most advanced simple countdown timer for Windows.
Tomato Timer - TomatoTimer is a flexible and easy to use online Pomodoro Technique Timer
SnapTimer - SnapTimer is a simple, free, portable countdown timer for Windows.
Tasklog App - Tasklog App is an agile productivity software designed to meet the needs of current world freelancers.
Be Focused by XWaveSoft - Simple Pomodoro timer in your Mac's menu bar
YAPA - Pomodoro timer