Avery, which offers SDKs for Android and iOS, has announced that it is now available on Windows Phone as well. The tools are actually free for developers, with the company instead planning on sharing revenue with its premium content partners.This app has a good chance of being the first to receive in-app purchases on the platform. The SDK is currently being used by the Rowi app and Rekap, with others having announced plans to incorporate it going forward. [Source Geekwire]