Developers including Tapulous, Glu Mobile, ComiXology and Trendy Entertainment already supporting it.
Google has officially launched its Android in-app billing system, but for now it will only work within apps and games distributed through its own Android Market.
The launch comes just days after Google started letting developers submit apps in readiness for the consumer launch, which came yesterday. "As an Android developer, you will now be able to publish apps that use In-app Billing and your users can make purchases from within your apps," blogs Google's Eric Chu.
He lists several Android apps that are already using the in-app billing, including Tap Tap Revenge by Disney Mobile; Comics by ComiXology; Gun Bros, Deer Hunter Challenge HD, and WSOP3 by Glu Mobile; and Dungeon Defenders: FW Deluxe by Trendy Entertainment.
Glu's official documentation for the new in-app billing makes it clear that "In-app billing can be implemented only in applications that you publish through Android Market". That's not a huge surprise, but it does pose a question for developers who want to use IAP in their apps, but also distribute them in other stores, such as GetJar and the Amazon Appstore.
Developers are also warned that they cannot use in-app billing to sell physical goods, personal services or anything that requires non-digital delivery.