How to implement app purchase in Android app?

What are the ways to implement virtual currency/coins/points in an android app?

• I am developing a chatting kind of an android app which would require coins/points/virtual currency implementation in it. Is there any API that provides this implementation ? What is the best way to implement this functionality

• Answer:

  OS APIs will only help you make transactions with hard money - through their proprietary store. If you want to create soft currency, then you would need to write it yourself within your application. Let's say you have 2 different types of "soft currency", i.e. virtual currency, you will keep track of it yourself, on a per-user or per-device basis. If you are planning to monetize (i.e. sell some of this soft currency in exchange for real money), then you will need to have a conversion system that will trade in real cash for your virtual currency. Let's take a simple example. Let's say your app lets you edit pictures you take from your phone's camera. Let's say it allows you to only edit one photo everyday (for free). Every additional photo that you want to edit on that day requires you to pay 100 virtual coins. Let's assume the app also has additional content that you can buy - a one time purchase. For example - the app has many different filters that you can use on your photos - but only after you unlock (buy) them. You buy these filters by paying, let's say, 1 gold gem. Now, the important part is that the app's ecosystem has absolutely no idea about real world currency. All it knows is that the user needs to pay 1 gold gem to unlock a filter - and the editing of one additional photo everyday costs 100 gold coins. Now, it is up to you, as the developer of the app to define how the user is going to get these gold coins/gems. He can either (i) straight up pay for the coins and gems (ii) wait for a period of time so that the gems and coins accumulate (if you give them out at regular intervals) or (iii) earn coins/gems through completing tasks (such as inviting friends, liking pages or watching ads). Note, again, that the user is rewarded with... yes, coins and gems, NOT a filter or a free photo edit for that day! I hope this explains that the ecosystem of the app and the store are different - and that you will need to build your own virtual currency system.