Facezam can identify people by matching a photo of them with their Facebook profile. All users have to do is take a picture of someone on the street and run it through the app, which will tell them who it thinks the person in the photo is.
"Facezam could be the end of our anonymous societies," said Jack Kenyon, founder of Facezam. "Users will be able to identify anyone within a matter of seconds, which means privacy will no longer exist in public society."
Facezam scans billions of Facebook profile images a second, which it accesses through a database for developers, until it finds a match. It claims to be able to link most photos with a profile on the social network within 10 seconds.
The app, which will launch on iOS on March 21, has been tested on more than 10,000 images to date with a 70 per cent accuracy.