TimeLeft - TimeLeft is a versatile desktop utility - it can be used as a countdown clock, reminder, clock...
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.
Dial - Quick & beautiful macOS timer.
Timer Tab - Online countdown timer, alarm clock, and stopwatch.
T-Clock Redux - T-Clock Redux in an enhanced fork of Stoic Joker's T-Clock 2010 with ISO week number support...
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.