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.
Time Doctor - Time Tracking and Time Management Software that is accurate and helps you to get a lot more done each day.
Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.
RescueTime - Time management software that shows you how you spend your time & provides tools to help you be more productive.
Hubstaff - Simple yet powerful employee work tracker with screenshots, timesheets, billing, in-depth reports, and more. Understand productivity issues and act on them.
TimeCamp - Simple and robust time tracking app to help you stay on the same page with your team while working from home.