Tapping adds apparently lead to installing these things called "Launcher" which are essentially complete phone UI and those launchers have ads that lead to even more hideous apps. They also lie about the thing you are installing, she was trying to get some emojis and I checked back then, the launcher in question was disguised as emoji thingy. You need to carefully read the text to understand that you get the emojis together with complete phone UI replacement.
I can't stand the Android way of doing things. How it is possible to replace the main user interface of the device? I understand the desire to completely control your device and I do support it in principle but this sort of modifications should be possible only by going through scary screens that let only people know what they do achieve that sort of device modifications.