A free way to transfer all your music from your iPhone to your computer. Must have the desktop counterpart running concurrently to receive the music on your computer. This program can be found here https://github.com/jault3/MusicTransfer-api.
Currently you must clone that api project, open up terminal, navigate to the root of the api project, run ./gradlew run. In the near future it will become easier to run. (Probably opening a .app and clicking a Start button). These directions are also in the README of that repository.