Game Circle that allows users to add to the game experience. Then, there is the New Maps API that allows for integration of maps into apps that run on Amazon Kindle Fire and the Amazon Kindle Fire HD. Test Drive on Kindle Fire has been around for more than a year and lets customers test out an app before buying it. This is now available on the Amazon Kindle Fire HD and Amazon Kindle Fire HD 8.9. What if you write apps for the Amazon devices but don't own them? You can use the Kindle Fire Emulators that will allow you to test your apps.
Amazon also released some very interesting stats. Perhaps the most important one is that downloads from the Amazon Appstore are up 500% year-over-year which is very promising, especially if you're an Amazon developer, stockholder or Jeff Bezos. Since the launch of the Amazon Kindle Fire HD, the number of GameCircle enabled games has doubled and the number of apps offering in-app purchasing doubled from the start of Q3 to the end. It sounds like Amazon has everything under control for Kindle Fire users who might not be missing the Google Play Store at all.
source: Amazon via AndroidCentral