Log what you do on your computer. Simple (yet powerful), extensible, no third parties.
- There's automatic logging, just like in Recuetime. But unlike Rescuetime, your data is yours as the app is 100% open source, so IMO it is better suited for most corporate privacy policies and hence better for GDPR complience. Rescuetime is fine if you are a home user and don't care about privacy, but due to EU privacy law, it is not suited for the corporate environment in the EU.
- The spirit and attempt is same - But ActivityWatch is more an alternative of ManicTime and not RescueTime. RescueTime uses crowd sourcing for tagging - and this is missing in ActivityWatch
- Open source, really tracks lots of stuff, no hidden paid option once you're accustommed to it, huge efforts for making it work on Windows, Mac AND Linux, tracks stuff in web browser too