The controversial app for avoiding crime in your area is back in the App Store, and it's now called 'Citizen'

Last October, a new app appeared on the App Store aimed at preventing crime.

Called Vigilante, the app showed users where crime was happening in real time - and seemingly encouraged them to help stop it.

Vigilante went viral in less than two days, spreading quickly due to a controversial video that showed someone using the app to prevent a would-be mugging, filming the incident and scaring the assailant away.

But Vigilante had a short life span: The app was pulled from the App Store about 48 hours after it launched due to safety concerns.

Now, Vigilante is back on the App Store as Citizen, a crime avoidance tool for metropolitan areas. Here's how it works.