Back to my old habits, I downloaded a game from an ad that looked interesting.
The first thing that appeared after opening the app was a subscription pop up... yeah it's a mobile game alright.

There's an ad in every single screen of this game pretty much. You doing anything = an ad, plus you get opportunities to watch more ads to get more rewards!
It's actual gameplay is alright and I got to enjoy it more while on airplane mode, but I bet there's a better game just like this for free on newgrounds.