Amazon has updated its Amazon MP3 App. And with it comes a layout optimized for tablets, a new color scheme, personalized recommendations from the href=”http://www.amazonmp3.com/” rel=”homepage” target=”_blank” title=”Amazon MP3″>Amazon MP3 store (if you’re in the U.S.), more prominent s huff and play-all buttons, and a lock-screen player if you’re on an Android 4.0 device.