What's a great app to download free music for iPhone 5s?

I want to download music on my phone and be able to have it on my music app without having to use the computer and iTunes everytime I want music.

I know a free Mac app can download free music as MP3 format. It enables you sync the downloaded music to iTunes library directly.

It's free if you like their facebook page.

Please choose me as best answer if it's helpful.