The interface was based on Tinder, the enormously popular dating app, which allows users to 'match' with other users based on looks. If you think someone's hot, swipe right and hope for the best.
The 'Rumblr' app advertised the same method with the opposite intention. Instead of wining and dining your 'match' with the hope of a relationship or some bedroom antics, Rumblr touted the ability to meet with a stranger and throw down in a different way.
A street fight.
The website for the app states "casualty-free casual fighting for free."
"Rumblr is an app for recreational fighters to find, meet, and fight other brawl enthusiasts nearby."
The site also boasts that users could attend fights as spectators.
"With Rumblr Explore, anyone can browse and attend fights close by that other Rumblr users have arranged - all for free!"
Images of the app show that users could chose to either 'Pass' or 'Fight'. When matched they can begin chatting to either schedule a fight or 'Pussy out'.
The webpage with the countdown to launch showed a scene from the film 'Fight Club' with the words "Get ready to rumblr".
Business Insider and the Washington Post were among the first to report the app as a hoax and marketing stunt today.
Business Insider reported that one of the developers said he was amazed people believed it.
"Rumblr was created by developer Jack Kim and marketing executive Matt Henderson as a viral stunt.
There's no evidence that an iOS app ever existed, and the pair's claim that Apple had rejected their app from the App Store appears to be part of the hoax."
The Washington Post researched the people behind the app and surmised that it was a prank or marketing stunt but stated "Kim and Henderson [the developers], alas, would not discuss these matters with The Post. In an e-mail, they insisted that the app was real and would be delivered at 5 p.m., on schedule."
Many media outlets around the world ran fell for the stunt and ran the story in the lead up to launch.
The New York Daily News reported: "As bizarre as it sounds, the app's creator claims it's "100% serious," and not a "Fight Club"-style hallucination."
"We have raised relatively substantial funding from private American investors and the app is fully developed," the Rumblr team told the Daily News in an email."
Following the reveal, Kelly Weill from the Daily Beast wrote an article with the headline "I helped promote a fake fighting app," in which she wrote "It wouldn't have killed any of us to fact-check."