Yes, 하다 - 매출을 이롭게 is completely free and it doesn't have any in-app purchases or subscriptions.
Not enough reviews to make a reliable assessment. The app needs more user feedback.
하다 - 매출을 이롭게 is free.
To get estimated revenue of 하다 - 매출을 이롭게 app and other AppStore insights you can sign up to AppTail Mobile Analytics Platform.