Right when I started building a custom F-91W with/for my kids based on sensor watch: https://github.com/joeycastillo/second-movement

I'll take some solace in mine supporting lots more alarms (beep when school recess ends) and a bunch of geeky stuff like sunrise, moon phases, tides, and stuff.

The sensor watch is actually awesome, if only for turning a cheap casio into a super-accurate quartz watch with temperature compensation.