[iOS] Guide open the "ghost cat" hidden hidden in the Speedtest application

Today, at the forum Sforum.vn, a user accidentally discovered the application Speedtest on his iPhone suddenly haunted and appeared the cat icon with the sound "haunted".

However, the "ghost cat" only appears only when the user long hold on the Go icon on the Speedtest application. At the moment, this feature is only available on iOS and has not yet appeared on Android and the web platform.