Mac music library app

To date, it is still not possible to edit song metadata on an iOS device, nor it be recommended if it was possible. Songs you get from sources directly onto the device (Spotify, GrooveShark, iTunes Store) all contain correct information. If you have damaged metadata inside media you've acquired elsewhere, look into software that will clean it up before syncing it over.

From what I see using Vox, it does not create a library of its own, instead it either access the iTunes Library directly for information.

It should be a read-only access, and you have nothing to worry.

You should note that it's not iTunes integration, so it does not work with iTunes Match to provide tracks that aren't downloaded to your Mac yet.

If you have further concerns, I suggest you contact the developers of Vox directly.