"This wasn't a formal release -- this was something that a few engineers were testing. With all tests, some get released as full products, others don't. Nothing more to say on this for now," a Facebook spokeswoman said in an email.

Still, the location-based feature marks a foray into the new territory of social discovery, or finding new friends, for the social network, which acquired the social discovery app in May.

"This is Facebook capitalizing on the popularity of applications like Sonar, Highlight and others that provide a similar social discovery service to bring some value from location based services," Chris Silva, an analyst with Altimeter Group, said in an email.

But the move didn't immediately trigger concern among industry players that Facebook would crush existing apps.

"Bringing more attention to location-based services and technology is a great thing," Damien Patton, the CEO of , said in an email. But he suggested Facebook had more work to do.