I just got a chance to try this - looks nice!
I guess for something pre-installed, people won't actually see any of the text that appears (initially) - and when they get to that point they could easily have loaded up your code themselves.
(just an aside, but if I added
https://www.espruino.com/ide/#code_url_here it could be really helpful for posting up code?)
So I'm wondering what we could do 'out of the box' - when you first insert the battery and do nothing else - that would be fun, and that didn't drain the battery for those that turn the Puck on and then just leave it (including if they put it in a bag and the button kept being pressed).
The rainbow is nice, and maybe it could detect rotation using the magnetometer.
Perhaps it could flash out rainbow colours in 4 groups of pulses, where the number of pulses corresponded with the Puck's MAC address that was displayed when advertising?
It'd be nice to it to be able to connect to Pucks that are very close (high signal strength) and make them flash or something - but I think in a classroom environment that would just be more annoying than anything else :)
I guess after an hour of not being used it could just completely clear itself so it went back to not using much power?