Martian SlingShot is described as 'SlingShot 2.0 adds support for synchronizing Playlists of music from iTunes. It works just like you might think: you Publish an iTunes Playlist from one computer, and then Subscribe on another' and is an app in the Backup & Sync category. There are three alternatives to Martian SlingShot for Mac and Windows. The best alternative is SuperSync, which is free. Other great apps like Martian SlingShot are CopyTrans TuneSwift (Paid) and NetSync for iTunes 2 (Paid).
CopyTrans TuneSwift automatically backs up and transfers your iTunes library from one PC to another drive, another PC, or Mac. You can move all library contents like music, playlists, videos, apps, books, podcasts, ratings, artwork and iOS backups.