This app is not new, it has been in existence for two years, but it has gone viral lately. An equally popular app, both among average people and among celebrities. Recently circulating news, one may say that this app is compromising the security of whoever is using it, because the face app collects personal information. Again, there are also options for deleting personal information from their server.
The fact is that this application has become a tendency among everyone, and has been explained by social media experts as a "shock value". It is primarily fun for those who use it and they enjoy it. Although the age-related appearance assumption provided by this application is most likely incorrect, this is obviously not the point. It seems to have more to do with the phenomenon of selfies, only with the added option of how we will look in a few decades. So the passion for selfies, first and foremost, with plenty of fun.