Defonic - Create a unique sound environment at home or in the office

Be Focused by XWaveSoft - Simple Pomodoro timer in your Mac's menu bar

Noizio - Feeling that the noise of the big city is too much for you to bear?

Ambiently - White Noise to help you concentrate, focus & relax

Noizer - Ambient sounds like Noisli, but free

Pomodus - A Pomodoro app that is integrated with Slack so that you can focus without Slack or your colleagues interrupting you. It silences your notifications, let's colleagues know that you're busy & when you'll be done. View stats & export your history.