Timehacker - Automatic time tracking for self-improvement

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.

Staff Mapper - Staff Mapper accurately forecasts employee availability and is engineered to provide recommendations on project staffing, based on availability, skills, tenure, and feedback mechanisms. It's proven to increase utilization and productivity.

Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.

Loresome - Self-improvement meets gamification

Hubstaff - Simple yet powerful employee work tracker with screenshots, timesheets, billing, in-depth reports, and more. Understand productivity issues and act on them.