Gamesys has launched a controversial, real-money gambling app called “Bingo Friendzy” in the United Kingdom. It is reportedly the first gambling app that involves real money for Facebook.

The Bingo Friendzy app lets users play games for cash prizes. It features bingo and slots games, The Verge said.

Users have to be at least 18 years old, according to TechZone360. Only Facebook members in the United Kingdom can view the app. Sign-on is separate than just entering Facebook information.

The app, however, is marketed with graphics and characters which are possibly seen as similar to Moshi Monsters, a children’s social network, according to The Telegraph. Christian groups want a firm response from the U.K. Advertising Standards Authority.

“Gambling is age-restricted for a reason: children are excluded because they are vulnerable,” Toby Scott, a spokesman for the U.K. Methodist Church told The Telegraph. “It is especially concerning that Bingo Friendzy’s visual marketing is the kind that you see in children’s games, with bright colours and friendly characters. This appears to be a blatant breach of the ASA’s Gambling Advertising rules, which clearly state that marketing ‘should not be likely to be of particular appeal to children or young persons, especially by reflecting or being associated with youth culture'.”

Facebook will take 30 percent of the revenue from Bingo Friendzy, according to The Telegraph.

The game was developed by Gamesys of London.

"Real money gaming is a popular and well-regulated activity in the U.K., and we are allowing a partner to offer their games to adult users on the Facebook platform in a safe and controlled manner," a Facebook spokeswoman told the BBC.

Facebook has lost a lot of its stock value over the past few months and is searching for ways to improve profitability. Other games may soon be offered on the site.

Meanwhile, Zynga, a large but troubled gaming partner for Facebook, expects to introduce real-money gambling in 2013.