The location service Foursquare is bringing back the feature that made it a sticky app in the first place: the ability to become "mayor" of locations by checking in the most. Almost two months ago Foursquare promised to bring back its famous mayorships, and on Monday, the geolocation-based service finally delivered, releasing updates for the Apple iOS and Android versions of its Swarm social networking app that bring back the company's signature feature.

"You've been asking, and they're finally back! Starting today, you can earn mayorships again," said the update description for the iPhone version of Swarm. "Just check in more than anyone else and you'll unlock a brand new, shiny mayor crown. But watch out, because people will be trying to steal them from you."

The privately owned Foursquare got rid of mayorships last year when it split into two apps -- Foursquare and Swarm -- as part of a revitalization effort that turned Foursquare into more of a local directory and Yelp competitor and created Swarm to fulfill users' social and check-in needs. 

Although the Foursquare app remains popular among users, many have complained that Swarm is not as fun as its predecessor, and as a result, Swarm has low ratings on the Apple App Store. That's why Foursquare announced in May that mayorships would soon be back. 

To become mayor of a location, users must check in there more than anyone else over the previous 30 days, Foursquare said in a blog. "Only one check-in per day counts, and ties go to the reigning mayor," Foursquare said. "We’ve been tallying all of your check-ins from the past month, so go see if you’ve already proven yourself worthy of the mayor crown at your local spots."