Numberfy (Numbers in Spotify) for Chrome
More About Numberfy (Numbers in Spotify)
This extension adds numbers to the songs in your spotify playlists, songs (collection) and albums.
Configurable using the icon in your browser (see 4th screenshot).
If the extension stops working, let me know (email below).
This extension is Open Source and can be found here: https://github.com/LinusCDE/Numberfy