InstaAgent was an app in both the Apple App Store and the Google Play Store which claimed to show the user who was looking at their Instagram profile.
Never underestimate the vanity of millennials, since as many as half a million installed the app. It rose on the charts near Candy Crush levels. The developer was making money through in-app purchases, selling people information about the top viewers on their profile and so forth.
However, at the same time the app most likely had no idea who was actually viewing Instagram profiles, it was stealing credentials and transmitting them back to a remote server, as iOS developer David Layer-Reiss is credited with discovering. [...]