The app does not help if you are not a fluent Chinese speaker living in Taiwan, since all the instructions are in Chinese. Furthermore, the design of the app looks mediocre, which might discourage some users to use it. Most importantly, the app does keep track of some emotions of the user, but the questions are based on a weekly routine. I think there are too many questions too. I’d suggest changing the questions to a daily basis (for example, how did you feel today about something), and improving on design. There are some apps in the app store that already have both these features, so I would not choose to use this one. Yes, this app does keep track of your mood, but it’s not useful in the sense of there are way better apps on the market, simpler to use and beautiful looking too.