You can find the project on GitHub at github.com/franciscunha/sortify.

Using Sortify, you can choose a playlist as the source playlist, and then have the option to sort each track in it. When sorting, you choose destination playlists to add that track to. When sorted, tracks are added to the other playlists, removed from the source, and added to your liked songs.

I wrote this simple application in under a week to learn the basics of Rust. The borrow checker does take quite a bit of getting used to, and it is more well-suited to lower-level applications rather than something like Sortify, but I still quite liked a lot of what it offers, and will likely choose to build something else with it if I get the chance.