I love Rdio. All the music I want to hear (that happens to be available in their library) for $10 a month. It gets better. I can download the songs to the mobile Rdio apps for offline listening. Even better still, there's an Rdio API and it's pretty rich, as described by Rdio's Ian McKellar in the video below.
Amazon has just announced the launch of Appstore Developer Select, a brand new program for developers that create Amazon Appstore and Fire OS optimized apps and games that use Amazon APIs such as GameCircle, In-App Purchasing, and Mobile Ads. The new Appstore Developer Select Program offers additional merchandising and promotion benefits to developers that create apps that meet the program qualification requirements.