I wanted to be able to randomize my playlist order in a more permanent way. I know there is a shuffle option but when I shuffle and continue playing on my phone, it re-shuffle's the playlist so I'll sometimes keep hearing the same songs over and over.
Once you authenticate with Spotify, your playlists will appear below. Select a playlist to change the order of songs and wait for a message. Easy peasy. Once it completes though, it can't be reversed by this tool. So make sure the list you want to change the order of is the correct one.
If it throws an error, it could possibly be caused by too many requests being sent to Spotify.