Yes, hisocana(ひそかな) 公式アプリ 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.
hisocana(ひそかな) 公式アプリ is free.
To get estimated revenue of hisocana(ひそかな) 公式アプリ app and other AppStore insights you can sign up to AppTail Mobile Analytics Platform.