The fastest growing game in smartphone history does not feature angry birds, Mayan temples or crushed candies. Rather it is an old school, rapid-fire quiz, which invites users to pit their knowledge of Harry Potter, the Twilight Saga ... and, well, whatever they like really, against eggheads around the globe.
Described as a 'cross between Trivial Pursuit and Wikipedia', QuizUp taps our latent desire to tout our cleverness to the world. You are invited to test your command of trivia against friends, family, Facebook chums, even complete strangers who share your field of interest.
With users generating and fact-checking their own quizzes, the game has already spawned a vast range of topics, from natural history and sports to obscure early 20th-Century horror writers.
The premise sounds stunningly simplistic -- which may explain why the Icelandic startup behind QuizUp initially struggled to attract capital. Nonetheless, QuizUp has become a sensation, leaving rival iPhone time-killers such as Angry Birds, Temple Run and Candy Crush Saga choking on virtual dust.
Some five million have downloaded the game since its launch in November. What's more, the rate of repeat play is high, with devotees spending on average 40 minutes a day putting their mental prowess to the test. Expect usage figures to rocket further as Android and iPad versions are released in coming months.
The story behind QuizUp has charming David versus Goliath undertones. It was created by Thor Fridriksson, a former TV presenter and struggling dotcom entrepreneur. With a Trivial Pursuit adaptation launched for iPhone in 2009, Fridriksson had assumed the trivia niche already over subscribed.
But then he saw an opportunity.
"We noticed no one had really dominated the market, which was strange, since trivia in its essence is a global phenomenon," he said. "When you're watching a game show with somebody and a question pops up on the screen, your first instinct is to shout out the answer to show off to that other person."
He went to San Francisco, beating heart of the dotcom industry, but nobody wanted to back a straightforward quiz game.
Unbowed he ratcheted up his campaign, literally following prominent venture capitalists as they went about their business in a bid to win them over.
Salvation came in the form of a moody teen vampire franchise. Having convinced Silicon Valley to pony up a little over a million dollars, he returned to Iceland and set his small team at Plain Vanilla games to work on a Twilight quiz. It was an instant hit and also signaled the ways in which QuizUp was going to differ from predecessors.
It would be a collective effort between creators and audience. The success of the Twilight version convinced Fridriksson the moment for a stand-alone version of QuizUp had arrived. Since it hit the iTunes App Store in November, Plain Vanilla has been inundated with 20,000 fan-made quizzes.
The game is free to download and does not feature advertising -- Fridriksson hopes to make money with sponsored quizzes along the lines of the Twilight tie-in.
With the game a phenomenon, he has found the financiers who refused to take a meeting in 2012 suddenly eager to do business.
If there is a cloud on the horizon it is that QuizUp's offering -- user generated trivia -- will be a cinch for bigger rivals to rip off.
"The speed at which companies get copied today is astounding," says Roelof Botha of Sequoa Capital, which recently secured a $22m investment for QuizUp.
"It's never been easier to start a company, but it's never been harder to build one."