Pro: It's a fun way to make friends.
Chances are, if you take your kid to the park anytime soon, there will be a huddled group of other children around staring at their phones. This is a cool way for your kid to make new friends their age with obviously similar interests (especially since it's Summer and school is out!) and for you to meet other moms of children equally as consumed with the game. It may seem like encouraging your child to stare at their phone and play a game isn't the best idea, but if it's what all the kids are doing, at least it can be social (kind of).