Can I transfer music on my iphone from app to app?

I do not download my music from iTunes. I have downloaded music on an app called mp3 music. But I want to transfer my music to another app that's cleaner, without ads and more efficient. Or even better, is there a way to transfer my music to the actual iphone music player?

IFile may work. Just locate the folder where the music is stored from the first app and copy/cut the mp3 to the folder where the music will be stored in the second app. But you need to be jailbroken to download iFile. You can also try iFunbox, same principle, but it is done with your iPhone plugged in to a computer.