I’m unsure if something like this exists, as I am yet to even join the Denon Eco system (making the switch from pioneer once the SC6000’s land here in the UK).
However, I hear Denon often read the suggestions found in the forums so its worth a shot. With the new capabilities of the Prime software I think it would be great to have a Mobile app which can sync your library across. Reckordbox have a similar thing but focusses mainly on setting hot cues and prepping tracklists, which is useful, but the app doesn’t let you continuously play a playlist track to track, not does it let you shuffle or even show track controls when the device is locked.
I find myself downloading numerous MP3’s everyday, analysing, setting hot cues, putting in the right folder on Rekordbox and then forgetting they exist! If I could sync my ‘recently added’ playlist from engine prime, or even a predefined playlist from prime to my phone, and be able to play it as though it was an iTunes playlist would be the dream.
Due to the nature of getting tracks from Bandcamp, Beatport, Soundcloud, etc MP3’s from all sorts of backgrounds, its impossible and incredibly time consuming to try and replicate your DJ library on your phone.
Would pay £££ to have access to an app like this, it would really help with knowing my library inside out and make me a better DJ in the long run.