Today, Google has announced on its Android Developer blog the immediate launch of the Android Market In-app Billing to developers and end users. In-app Billing gives developers and users more flexible ways to interact with apps, for instance, it allows the long overdue try-and-buy functionality but also allows to sell/purchase virtual goods, upgrades, and other billing models. Several apps launched today are already using the service, including Tap Tap Revenge by Disney Mobile; Comics by ComiXology; Gun Bros, Deer Hunter Challenge HD and WSOP3 by Glu Mobile
The Android Market does not yet indicating if an application features In-app Billing. Therefore, a free version of an app might ask for later payments. Also it not yet recognizable, if for instance a free version might be just a trial version which requires later In-app payments.
Cheers ~ Arne