You may or may not recall my Sidecar jacket for Simplify, the macOS controller for Spotify and iTunes (and others). Sidecar is my “Minimalist Yet Huge” version, and I still use it every day.
This is a companion discussion topic for the original entry at https://brettterpstra.com/2017/08/30/sideshow-sidecar-3-dot-0-for-simplify