Amazon's Appstore has offered a typical application acquisition experience, save for one important detail: in-app purchasing. Beginning today, devs can now take advantage of the familiar revenue booster already available in the iOS App Store and Google Play, through the use of the Amazon Appstore In-App Purchasing API. The service will enable Android device and Kindle Fire users to pick up expansion packs, virtual gaming currency or manage subscriptions from within individual applications, with the same one-click purchase experience available in Amazon's online store. A handful of top devs like Disney and Conde Nast hav