Any chance of pavlok support? It doesn't exactly vibrate but ... (and if the answer is "patches welcome" I can always make another attempt to convince my rpi to talk to the bloody thing myself)
I get a TON of requests about estim support, it's just difficult to figure out how ethics/liability works around all of that.
Your device is, probably not surprisingly, popular with a subset of our users. Especially your wristband form factor, though the fact that you've made it modular has ended up with some interesting 3d printed mounting solutions too. :D