ActivityWatch is a cross-platform open-source app that helps you track time to gauge your productivity. It lets you track the time you spent on applications, browsers, and if you were AFK (away from keyboard) or the system was hibernating.
Not just limited to tracking time, but it offers a bunch of useful features with visualizations that help you easily analyze how you spent time to potentially improve your productivity.
It’s a great alternative to proprietary options like RescueTime and ManicTime.
See Track Your Screen Time in Linux with ActivityWatch
ActivityWatch is an open-source privacy-friendly app that tracks how you spend your time on a desktop computer or on a mobile device.