I have a friend who made a secret folder on his phone and was wondering if it was through an app or if he rooted his phone. The folder is hidden, but when he taps the location (physical location) of the folder, a black screen shows up. After he taps the correct part of the screen, he needs to put in a password. Then he sees what's inside the folder. So I just wanted to know if an app did it (and if so, which app) or if there is some other method. Thanks.
