Marinara Pomodoro, a browser and phone app, helps me a lot.

This is not an advertisement for the app, it just works for me and my employees!

I click on the icon and concentrate on the task for 25 minutes, then take a 5 minute break. During that time I can go to the bathroom or get up and do some light exercise.

Then I press the icon again and continue working for 25 minutes.

You can choose to take a long break - 15 minutes if you need to do something around the house or have lunch, etc.

Most importantly, there are statistics and you can always see how productive you were or not.