The popular social trivia game QuizUp and its developer startup Plain Vanilla have been acquired by Glu Mobile, the developer of celebrity-themed games including Kim Kardashian: Hollywood, and Nicki Minaj: The Empire.

According to a SEC filing, Iceland-based Plain Vanilla had raised over $40 million in total funding, with Sequoia and Tencent among notable investors.

The deal is reportedly valued at $7.5 million, including forgiven debt, according to sources.

Plain Vanilla raised a hefty $22 million in its Series B round of venture funding led by Sequoia and Tencent in 2013. Altogether, the company had raised about $40 million in outside funding, according to Crunchbase, and had attracted tens of millions of users.

QuizUp, both a social networking platform and a mobile game, allows users to play trivia against friends, or strike a match in real-time against an equally skilled and knowledgeable player chosen by the game on a given subject. The game also lets users create their question and answer sets, something that will appeal to educators, fan communities, and brands looking for creative ways to promote their products.

Last year, QuizUp stopped being just a game after the startup launched a software that allows corporations to use QuizUp to deliver corporate training to their employees. The software also inked a deal with NBC for a show series of ten episodes based on and using QuizUp for audience-interactive elements of the show.

After NBC completed the QuizUp show in August, it was expected that Glu would eventually buy QuizUp since the startup could not find other funds from profits or new backers.

Speaking of the deal, Plain Vanilla CEO Thor Fridriksson said, "I hope that Glu will take good care of my baby."