[hashkb]

Harvest (and the hcl gem). Bonsai is supposed to be pretty good, too.

[hamzakc]

When I used to bill per hour, I used Harvest - https://www.getharvest.com/ and their mac app https://www.getharvest.com/apps/mac.

The great thing about the app is that if your computer is idle for a while it stops the timer. That was the most annoying thing that used to happen to me. When I went to pick up the kids or something I would forget to stop the timer. But the app automatically stops the timer and asks you to confirm.

I still use harvest to bill my clients using the invoice feature. Their free plan is all I have ever needed.

[mitchbob]

I've used Harvest, and I really like it. They have a free tier for 1 seat and up to 2 projects: https://www.getharvest.com/pricing

[derefnull]

I am also a happy customer of Harvest (https://getharvest.com/)