In-app Billing integration in Android

In-app Billing is a Google Play service that lets you sell digital content from inside your applications. You can use the service to sell a wide range of content, including downloadable content such as media files or photos, virtual content such as game levels or potions, premium services and features, and more. You can use In-app Billing to sell products as

• Standard in-app products (one-time billing), or
• Subscriptions, (recurring, automated billing)

When you use the in-app billing service to sell an item, whether it's an in-app product or a subscription, Google Play handles all checkout details so your application never has to directly process any financial transactions. Google Play uses the same checkout backend service as is used for application purchases, so your users experience a consistent and familiar purchase flow.

Any application that you publish through Google Play can implement In-app Billing. No special account or registration is required other than an Android Market publisher account and a Google Checkout merchant account.

For more detail on this you can check this link.

Here I have described a sample application that demonstrates how to sell standard in-app products and subscriptions from inside an app .