Gnome Pomodoro - This GNOME app helps to manage time according to Pomodoro Technique.
Pomodone - Pomodone is the easiest way to track your workflow using Pomodoro technique, on top of your current task management service.
YAPA-2 - YAPA-2 is a minimalistic desktop timer app for Pomodoro Technique users.
Pomofocus - A simple and customizable pomodoro timer for the web
Francis - Francis uses the well-known pomodoro technique to help you get more productive.
Tomato Timer - TomatoTimer is a flexible and easy to use online Pomodoro Technique Timer