FreelanceStation is a time tracking app for Mac specifically designed and built for freelancers. It has everything you need to work: easy manual time tracking, client, project and task management, estimate and invoice generation, payment recording and transaction exporting to accounting software.
TopTracker - Beautiful, free time tracking
Timemator - Automate your time-tracking and forget about the timer. Forever! Create your rules — tell Timemator which files you’re working on or what applications you use for your work... read more.
timeBuzzer - timeBuzzer enables freelancers and project-driven teams to track their time at the touch of a button, understand where their time goes and create reports with just a few clicks.
Qbserve - Freelance time tracking, invoicing, and productivity improvement
Cattr - Cattr is a free open-source self-hosted time tracker with desktop clients for windows, mac, linux.
Klokki for Mac - Rule-based automatic time-tracking