The VLC media player app is pretty decent - not the best UI ever, but it's pretty good for what it is. It'll play almost any audio file you throw at it, plus mo

The VLC media player app is pretty decent - not the best UI ever, but it's pretty good for what it is. It'll play almost any audio file you throw at it, plus most video files to boot. On iOS it's easiest to load media via the local webserver it runs for exactly that purpose, as apps are quite ringfenced when it comes to accessing data.