DMDJ uses a very sophisticated algorithm to playback more than 30 channels of sounds in the same time together with real-time effects and filters, in order to give you a AAA Game Audio experience.
To achieve that it uses hardware acceleration that it needs to run on mobile devices.
The makers of the devices don't allow hardware accelerated apps to run on the background and they have this feature locked for us the developers.
As soon as this will open, we will certainly and with no delay add this great feature.
Currently there is no official solution and we are working on that feature.