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.
Focus – Productivity Timer - The best Focus timer for becoming more productive every day! The Focus app helps you to stay focused and get things done by working with a pomodoro timer.
TomatoBar - World's neatest Pomodoro timer for macOS menu bar.
Francis - Francis uses the well-known pomodoro technique to help you get more productive.
YAPA-2 - YAPA-2 is a minimalistic desktop timer app for Pomodoro Technique users.