Yes, 商务英语口语高频话题 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.
商务英语口语高频话题 is free.
To get estimated revenue of 商务英语口语高频话题 app and other AppStore insights you can sign up to AppTail Mobile Analytics Platform.