Amazon.com today launchd the Amazon MP3 store optimized specifically for iPhone and iPod touch.

iPhone and iPod touch users will have access to digital music from Amazon?s 22-million song catalog using the Safari browser. Amazon also offers users personalized recommendations, best-seller lists and Amazon customer ratings. Music purchases are automatically saved to users' Cloud Player libraries and can be downloaded or played instantly from any iPhone, iPod touch, iPad, Kindle Fire, Android phone or tablet, Roku, Sonos home entertainment system, or any web browser.

Amazon 's MP3 store is offering everyday deals like $5 albums, $0.69 songs, and free songs from artists on the rise.

Amazon's move is part of a new initiative by the Internet retail giant challenging Apple's dominance of the digital music market.

Last week, Amazon launched a service that gives compact disc buyers instant copies of music in the Internet "cloud" in a challenge to iTunes. Amazon AutoRip provides free MP3 versions of music on CDs bought from the online retail titan.