The 20-20-20 rule for the eye is to relax eyes when working in front of a computer for long hours. As per this rule to relax eyes every 20 minutes look at some object 20 feet away for 20 seconds.
This application is for laptops and desktops. Every 20 minutes this application brings up a small popup at the system tray area to remind that it is time for 20-20-20.
The system should have Java Runtime Environment installed to run this application.