Does the iPhone 5 only support iTunes for music?

In short, I do not buy music through iTunes, I buy my music through Amazon.So, I use the Amazon MP3 downloader on my PC. Is there an app that I can download in the App Store that will allow me to use the Amazon MP3 downloader on the iPhone 5?

Just drag the mp3 to your itunes

ITunes will take MP3 files from any source including other stores, illegal downloads and ripped CD's.

If you can find the actual music files on the computer you can put them into iTunes and then bring them on over to the iphone. Most of these programs saves the music somewhere on you hard drive. I know where if it came from the iTunes store not Amazon so you would have to hunt that down yourself.