Yes, 有趣的汽車及汽車發動機的聲音 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.
有趣的汽車及汽車發動機的聲音 is free.
To get estimated revenue of 有趣的汽車及汽車發動機的聲音 app and other AppStore insights you can sign up to AppTail Mobile Analytics Platform.