Yes, 右脳を鍛える!逆さ計算!! 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.
右脳を鍛える!逆さ計算!! is free.
To get estimated revenue of 右脳を鍛える!逆さ計算!! app and other AppStore insights you can sign up to AppTail Mobile Analytics Platform.