Can I play tracks stored on my mobile device using the XDJ-RX3?

You can play tracks on the XDJ-RX3 if they're imported to rekordbox for iOS.
Note: You can’t play tracks from rekordbox for Android because currently the unit doesn't support the app.

You can use Mobile Library Sync and Cloud Library Sync to transfer tracks from your PC/Mac and the cloud to rekordbox for iOS so you can play them on the unit.

*Tracks from streaming services can't be played on the XDJ-RX3.

To connect the XDJ-RX3 with rekordbox for iOS, see [rekordbox.com]