I am often asked to recommend a good free/cheap program for tracking time spent on client work and projects.
I like TimeStamp, as do many other professionals I know. It’s quick to download and easy to use. Best of all, you can keep it running in the background and it doesn’t interfere with other programs you’re running.
At the time of posting this, TimeStamp is still free to download although a donation towards the site owner’s generosity is appreciated.