Yes, 新概念英语全册 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.
新概念英语全册 has several in-app purchases/subscriptions, the average in-app price is €1.99.
To get estimated revenue of 新概念英语全册 app and other AppStore insights you can sign up to AppTail Mobile Analytics Platform.