The social media giant has continued its recent series of purchases by snapping up the brains behind the Moves app, which uses smartphone sensors to track a user's activity, including distance travelled and calories burnt.
The app, which has been downloaded four million times since its launch in February 2013, was described as a "surprise hit" by Apple.
"The Moves team has built an incredible tool for the millions of people who want to better understand their daily fitness activity, and we're looking forward to the app continuing to gain momentum," a Facebook spokesperson said of the deal.
Facebook did not divulge how much it had paid to acquire Helsinki-based ProtoGeo, which was only formed in January 2012 and is thought to have fewer than ten employees. The acquisition is the latest in a series of deals by Facebook as it looks to utilise its vast cash revenues, having also bought instant messaging service WhatsApp for $19bn and virtual reality company Oculus for $2bn in the last few months
"Today, we're delighted to announce that Facebook has acquired our company and the Moves app," ProtoGeo wrote on its website, reassuring users that the app would continue to be a stand-alone service and not become an integrated part of Facebook.
"We're joining Facebook's talented team to work on building and improving their products and services with a shared mission of supporting simple, efficient tools for more than a billion people," it added.