世界历史地图集 is not free (it costs 1.99), however it doesn't contain in-app purchases or subscriptions.
Not enough reviews to make a reliable assessment. The app needs more user feedback.
The price of 世界历史地图集 is 1.99.
To get estimated revenue of 世界历史地图集 app and other AppStore insights you can sign up to AppTail Mobile Analytics Platform.