Have you tried to categorize music saved in your Spotify library using playlists only to find you can't see which songs aren't yet categorized? Organizing your music can be daunting if there's no way of knowing when you're done.
With Tagify, your existing playlists stay untouched, but a new playlist is created containing any music saved in your library which isn't also on a playlist with the prefix
Simply populate these new
tag:whatever you want playlists you create with songs, and watch them disappear from a new
tag:untagged playlist this tool creates which is simply your saved library minus your tagged songs.