I would like to request you extend the com.coppertino.Vox:// URL scheme on iOS to allow for playing specific media items, as well as adding them to the queue. I propose arguments such as title=, album= and artist= to indicate the requested songs.
More advanced commands to play radio stations or streaming URLs, or even an x-callback-url would allow for much greater flexibility in how I use Vox, but are not a priority.
Examples
Play album Random Access Memory
com.coppertino.Vox://play?album=Random%20Access%20Memory
Add album Her by Her to the end of the queue
com.coppertino.Vox://add_to_queue?artist=Her&album=Her
Send a list of all albums back to the Workflow app
com.coppertino.Vox://x-callback-url/getAlbums?x-source=workflow
Addendum
For anyone interested in this as much as I am, I will quickly document Vox’s URL scheme in its current form. After disassembling both the iOS and Mac app, I am confident that there’s not much to do with com.coppertino.Vox://, apart from launching the app. On Mac, Vox at least supports opening different views of the app:
com.coppertino.Vox://openloop
com.coppertino.Vox://soundcloud
com.coppertino.VoxPrefs://open