I was brainstorming how to use the Arduino micro with a minimum number of wired connections to a rotary encoder. It struck me that the micro is breadboard-compatible, so had pin spacing that could work with the rotary encoders that Adafruit sells. In fact, you can solder the rotary encoder right on top of the micro, "dead bug " style.
The first trick here is to align the pins from the encoder to micro pins that are also contiguous to each other. One side of the encoder, used for volume up/down, uses digital pins. The other uses Analog pins as digital pins.
Also, there are two required GND connections to make the encoder work. The second trick is to make a GND connection with analog and digital pins. You can do this by setting pins LOW:
Like the LeoStick, this works on Linux, Windows, Mac and Android.