Yes, 考研英语词汇打卡 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.
考研英语词汇打卡 is free.
To get estimated revenue of 考研英语词汇打卡 app and other AppStore insights you can sign up to AppTail Mobile Analytics Platform.