WorkTimer — Open Source Calendar App

WorkTimer is an app that helps you to structure your work time and to stay productive by applying the Pomodoro Technique®. You can set the duration of your work sessions, short breaks, long breaks and the ratio of breaks to work sessions. The app notifies you when a session is over and can even enable Do Not Disturb mode to prevent distractions. It also reminds you to drink water and can keep the screen on while in use.