As I finally have fiddled something together myself that fits in this category...
I built a little something over the course of the last evenings to solve a problem I was having: A little remote control for my Sonos installation. ESP8266 in the shape of a Wemos D1 Mini, rotary encoder, Micropython (which I finally wanted to try out), Sonos HTTP API and a 3d printer for the case parts = win
It's not much to look at, but it makes volume changes, play/pause toggling and track switches so bloody convenient. And I dimensioned it so I should hopefully also be able to build a waterproof-ish version to mount high up in the shower since it should fit run-of-the-mill rubber o-rings (in that case though I'll do the powering not through the exposed micro usb plug but rather a sealed in cable).
I've thrown firmware & STLs up on github here:
Should be enough documentation in the README to build one yourself if you need to