MOBILE applications get really interesting when money changes hands. The initial sale of your application is one way to make money, but applications that allow their users to buy things open up many more possibilities. Here are a few:
You could sell a game with two or three levels and allow users to buy more levels. You could even distribute the game application for free to get people hooked and then make money by selling levels or other upgrades.
An online store client could enable its users to order items and pay for them.
A client that connects to a pay service could allow users to pay for additional service directly.
The JSR 229 Payment API is a flexible API that enables applications to make payments on behalf of their ...