How old is the article inside the question from habr?

Question

Android

How relevant is this article on Habré ? Are there any, albeit in English, guides for:
• beginners,
• ignorant,
• idlers,
who would meet today's criteria for introducing InApp Purchase into your application?
An article from 2013, comments too, and the implementation of advertising itself is not clear, since I myself use a slightly different method provided by Google itself.
PS : An additional question, will the percentage of purchases of PRO versions of applications depend on whether the purchase is implemented in the application or leads to a separate one on Google Play?