(Not Boring) Timer - (Not Boring) Timer, a fascinating time tracking application that will let you stay on top of your task and remind you about the important events coming up on the same day.
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.
Chronograph.io - Cloud synchronized stopwatches and timers.
Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.
MultiTimer - The new application available on the App Store|Subscribe
RescueTime - Time management software that shows you how you spend your time & provides tools to help you be more productive.