Online Stopwatch is a simple collection free, web-based stopwatches, timers and clocks. No log-in or username is required. You just choose a favorite stopwatch, set the time to count up or down and off you go! I like to use this free resource with students when they are working in small groups. I usually have the stopwatch count down the time. With it flashed on our big screen, students can easily see how much time is remaining to work with their group mates.
This one below is called the "egg timer." I would have named it something else....
This one, a favorite of students, is the bomb timer. It does ring at the end, but does not sound like an explosion.
See which stopwatches, timers or clocks you find useful at Online Stopwatch.
....Pretty good at limiting my text today, wasn't I?