TinkerTool - Tinker with the hidden settings of your Mac
Toggl - Toggl is an online time tracking tool. It features 1-click time tracking and helps you see where your time goes. Free and paid versions are available.
Onyx by Titanium - This website provides operating system utilities for macOS
Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.
Cocktail - General purpose system modify/repair utility
RescueTime - Time management software that shows you how you spend your time & provides tools to help you be more productive.