Hourglass - Hourglass is the most advanced simple countdown timer for Windows.

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

Online Alarm Kur - Free online alarm clock, set alarm easily on your computer using the internet alarm clock without downloading any software, wake up in time with the loud online alarm clock.

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.

KukuKlok - Kukuklok is a free alarm clock available online and offline.

Pomodone - Pomodone is the easiest way to track your workflow using Pomodoro technique, on top of your current task management service.