They used to have a “Lite version“, however they recently changed their policy. Full explanation available here.
There is a 2 week free trial period available at rescuetime.com
RescueTime is an app you install on your computer and mobile devices that automatically pays attention to the apps you use, which files you open, and what websites you visit.
It logs how much time you spend in each of them.
RescueTime helps you protect focused work time and set healthy boundaries.
It aims to help you achieve work/life balance by shedding light on how you spend your time, improving your focus, and helping you find more time for the things that matter most.