Free to play
Global mobile app revenue in 2016 was $88.3 billion and is estimated to grow to $188.9 billion by 2020. The top grossing iPhone mobile gaming app in the United States as of August 2018 was Fortnite with a daily revenue of $1.8 million dollars, followed by Candy Crush Saga with $1.3 million and Pokemon Go with a million dollars. (http://bit.ly/2DcDG1x, http://bit.ly/2DuyMxK)