Don't wanna use itunes just a free music downloader?

I want an app to download music on my iphone I know it won't download to the stock music app but the music app but I need an app that won't use data when listening to the music i've downloaded

Just look up Mp3 downloader in the app store. It sucks that apple made it that way. (Honestly though it's better to just get Itunes on PC and use it to transfer mp3 files)