Yes, 고사성어 퀴즈 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.
고사성어 퀴즈 is free.
To get estimated revenue of 고사성어 퀴즈 app and other AppStore insights you can sign up to AppTail Mobile Analytics Platform.