In-app purchase is a feature through which the application's component can be bought from inside the application with the help of several payment gateways. This is one major aspect of monetization for Android games.
In the modern day gaming industry, freemium games are booming. This means users can play the game for free, but they have to pay for certain components or for game progression advantages. This model has been proved to be a success, as it supports both free and premium concept in terms of digital gaming.
In-app purchases serve this purpose perfectly. We have already discussed Google In-App Billing services, which is just a means of in-app purchasing through Google. But there are other services that support the same thing.
In general, a game should offer in-app purchase items to give users a choice to buy the following types of content:
Unlock certain features in the game
Buy certain items to get an advantage over other players...
