My understanding of this app is : it made for people who wants to lose weight but lack of willpower. One can do self-supervising by tracking what he had eat/drink everyday through this app. Also, as a social media, it also allows mutual supervision between you and your friend. But somehow, it turns out that many people used it as a secondary Instagram. It takes people more time and energy for plating food as well as shooting pics. The purpose of tracking what had been eaten can easily be accomplishment by opening a icloud photo fold or make some note. Besides, the app is extremely slow. It shows "loading" for every step which is quite annoying. But I have to say its a fun app. But I will delete it very soon.
Kyle Sheng about YouFood Photo Food Journal, v2.2.8