BreakTimer is described as 'Save yourself from RSI and eye-strain
BreakTimer allows you to set up customizable breaks and will remind you to take them.
BreakTimer is free and open source and available for Windows, macOS and Linux' and is a Prevent RSI app in the sport & health category. There are more than 50 alternatives to BreakTimer for a variety of platforms, including Mac, Windows, Linux, iPhone and Flathub apps. The best BreakTimer alternative is Stretchly, which is both free and Open Source. Other great apps like BreakTimer are Workrave, Loook, Glance - Prevent Eye Strain and Micro-Break.