In-App Billing: Putting a Store in Your Application
Roy Sandberg, Mark Rollins · Apress eBooks · 2013
In-app billing allows a developer to charge users for app features after their app has already been downloaded. Imagine charging users for more levels of your game or charging them for virtual goods (such as a magic sword in a game). For non-gaming apps, you could charge for special features or even per use if the use case is strong enough. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.