I was looking for a device with two LCD digits that could count down 20, 30 and 60 seconds. 20 seconds is for hand-washing. 30 seconds is for brushing teeth (you're supposed to spend 30 seconds on each top/outside, top/inside, bottom/outside and bottom/inside.) 60 seconds is how long I'm supposed to swish my fluoride rinse.
The idea is simple, you press one of the buttons and a 20, 30 or 60 second timer starts and an LED illuminates, making the LCD background green. When the timer gets to 5 seconds, it turns yellow. When it gets to 0 seconds, the background turns red and it beeps for 2 seconds. After those two seconds complete, the background LED is turned off and the beeping stops.
There's a three-way switch with positions: beep, custom and silent. When it's in the "beep" position, it will beep when the timer expires. When it's in the "silent" position, it will not beep. The "custom" position is reserved for future use, but for now, it does the same thing as the "beep" position.
There's also a "SILENCE" button you can press if you forgot to flip it over into "silent" mode and don't want to listen to it beep.
Here, try it yourself. I was originally thinking a thumbwheel on the side for the silent / custom / beep selector, but implemented it as radio buttons here.