Yes, 九宫格数独app is free to download, however it contains in-app purchases or subscription offerings.
Not enough reviews to make a reliable assessment. The app needs more user feedback.
九宫格数独app has several in-app purchases/subscriptions, the average in-app price is EGP 216.55.
To get estimated revenue of 九宫格数独app app and other AppStore insights you can sign up to AppTail Mobile Analytics Platform.