android – Amazon FreeTime Unlimited Monetization

I have therefore recently noticed how FreeTime Unlimited is great for my daughter. There is no advertising, no in-app purchases, and so on. She can just play games / apps and I do not have to worry about them.

As a development, I think this might be an interesting avenue, but there are a few things that I can not for all my life not be able to get logical support / Amazon forums to logically answer.

Thus, according to their information, the applications are thoroughly examined to verify that they are content adapted to children, which is excellent. In addition, you can not use web views, ads, or in-app purchases.

My question is: How developers are monetizing these applications? Clearly, they do not just give their work for free? The only logical answer I can guess, is that it uses the Amazon Underground computing system which is to make money based on the time that the user goes into the application / the game.

Does anyone have real experience or information about it? As I said, I have contacted many people at Amazon and I continue to follow the thread of discussions by showing me the same useless link.