Yes, 腕式血氧记录仪 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.
腕式血氧记录仪 is free.
To get estimated revenue of 腕式血氧记录仪 app and other AppStore insights you can sign up to AppTail Mobile Analytics Platform.