Spotify Mini Player is described as 'Get easy access to the controls for the Spotify Web Player from the Chrome toolbar. You do not need to jump to the Spotify tab each time you want pause, stop or skip the song. Once you launched Spotify Web Player in your Chrome browser you can forget about that tab' and is an app in the Web Browsers category. There are three alternatives to Spotify Mini Player for Mac, Alfred and Linux. The best alternative is Spotify TUI, which is both free and Open Source. Other great apps like Spotify Mini Player are Alfred Spotify Mini Player (Free, Open Source) and SpotSpot (Free, Open Source).
Spotify for the terminal written in Rust 🚀. Spotify-tui needs to connect to Spotify’s API in order to find music by name, play tracks etc. Instructions on how to set this up will be shown when you first run the app.
SpotSpot is an open source (MIT license), always on top, mini-player for controlling Spotify in macOS. It is an Electron-based app, and utilises André Haveman's excellent Spotify-Node-Applescript package to connect with the Spotify desktop app.