Hourglass - Hourglass is the most advanced simple countdown timer for Windows.
Timer Tab - Online countdown timer, alarm clock, and stopwatch.
Alarm Clock Tab - Web based time tools including alarms, timers, stopwatch, and time zone converter. Resources also include Tabata, Pomodoro and other useful tips and tactics for managing time and time tracking.
Online timer - Online timer is a free and easy-to-use tool that comes with a very simple way to get done with measuring time and alarm.
Online Stopwatch - Online Stopwatch is free to use online tool that allows you to keep track of the important events and tasks that you are performing.
Gestimer - For those little reminders during the day