Chances are you haven’t heard of social game maker Wooga. But thanks to the popularity of its social game Diamond Dash, the German company is now the third-largest social game maker on Facebook. Now the company is preparing to take Diamond Dash into the hot mobile games market.

Berlin-based Wooga has more than 35 million monthly active users on Facebook, behind only Zynga with 266 million users and Electronic Arts-PopCap Games with 48 million users. That’s a pretty big achievement for a company that didn’t exist until a couple of years ago.

Wooga’s move into mobile games makes sense because there’s a mad rush into mobile games, which is one of the wide-open battlegrounds in the game market. By moving into mobile, Wooga is following a model that many successful social game companies have tried.

Besides Diamond Dash, its hits include Monster World, Brain Buddies, Happy Hospital and Bubble Island. Brain Buddies was the first game the company launched on Facebook, and it hit 4 million monthly active users in its first eight weeks in the summer of 2009.

“We do very few games with very high quality,” said Jens Begemann, chief executive, in an interview earlier this year. “Very few people know us.”

The company made its announcement at the Casual Connect game conference in Seattle today. Wooga’s Diamond Dash has more than 10 million monthly users, and the company has had 300 percent active user growth in the past 12 months. Wooga is now planning to publish the title, which is the 10th most-popular game on Facebook, on Apple’s iOS.

Back in May, Highland Capital Partners led a $24 million investment round in Wooga. Other investors, Tenaya Capital, Balderton Capital, and Holtzbrinck Ventures, also participated. Wooga stands for “world of gaming.” The company was founded by Begemann in 2009. From the start, he focused on Facebook based on what he called the Frank Sinatra strategy: “if you can make it there, you’ll make it anywhere.”

Wooga said it is also looking to create original HTML5-based mobile game titles. HTML5 is a standard format for web games that many hope will become the lingua franca of cross-platform apps.