Yes, 我的情緒日記:紀錄每日情緒變化 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.
我的情緒日記:紀錄每日情緒變化 is free.
To get estimated revenue of 我的情緒日記:紀錄每日情緒變化 app and other AppStore insights you can sign up to AppTail Mobile Analytics Platform.