Activity Watch - Free No Effort Time Tracker

Activity Watch is a free no effort time tracker that can keep track of how long you use every app on you Mac while running in the background. You can categorize your apps so that you can see how much time you spent working, gaming, choosing music or watching video. There are browser extensions that work with it to break down your time per tab if you desire that kind of granularity. The app runs in the background and the results can be viewed in your browser at localhost:5600. It is open source, cross platform, privacy first and a great alternative to services like RescueTime, ManicTime, and WakaTime. 

Aside from the informative reports and graphics in the web interface, you can also download all the data collected as JSON files. Other useful features include a built-in stopwatch for you to use as you see fit and a timeline view.

The views available on the report page include:

• Top Applications
• Top Window Titles
• Top Categories
• Category Tree
• Top Browser URLs
• Top Editor Files