Hourglass - Hourglass is the most advanced simple countdown timer for Windows.
Time Doctor - Time Tracking and Time Management Software that is accurate and helps you to get a lot more done each day.
Free Alarm Clock - Free Alarm Clock is a free, full-featured and user-friendly computer alarm clock for Windows.
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.
wnr - Better than pomodoro, this timer app balances work and rest.
Hubstaff - Simple yet powerful employee work tracker with screenshots, timesheets, billing, in-depth reports, and more. Understand productivity issues and act on them.