on the ads part, its harmful yes, but i disagree on your last comment.. its not a trash tactic. paid version makes faster progress, not paid one is a normal progress. this system is almost everywhere in many games..
With respect, it's a trash tactic in ANY GAME. Specifically, a shameless cash grab tactic. That's literally saying "Well, other games use micro transactions, so it must be moral for me to do it as well."
Landlords use this logic with raising rent, and it makes them scumbags - be better than landlords.
Edit: Checked the dl link - HOLY SHIT THAT'S SKETCHY. IT'S LIKE YOU WANT US TO INFECT OUR DEVICES.