It didn't land in the Marketplace yesterday as announced, but Amazon's Audible audio book app for Windows Phone 7.5 is now available for download. This Metro-fied version of the app is free to install (including some short samples to get you started), and signing in with your Amazon account lets you purchase any books that the service has on offer. Media can be controlled using a swipe gesture interface, and there are even varying levels of badges to reward how much of a book-worm you become. All that said, we haven't been able to use the voice control functionally
