Facebook today closed a deal to acquire Glancee, an ambient mobile location app that alerts users when people with similar interests are nearby, according to an announcement on Glancee’s website.

Co-founders of the San Francisco-based startup — Andrea Vaccari, Alberto Tretti and Gabriel Grise — will join Facebook, but other terms of the deal were not disclosed. Glancee has already been removed from the Apple App Store.

This is the social network’s third mobile acquisition since filing for an initial public offering. The company bought mobile photo sharing app Instagram and mobile loyalty startup Tagtile within a single week in April. These, along with the six mobile acquisitions made last year, signal that Facebook wants to bring top mobile talent and technology to its company.

Glancee’s iPhone app let users sign in with Facebook, and then it would show users other people who have things in common with them within a certain radius. The app had 20,000 monthly active and 3,000 daily active Facebook-connected users, according to our AppData tracking service. Its competitor, Highlight, has 80,000 MAU and 9,000 DAU.

Unlike Instagram, which is continuing as a standalone application under its own name, Glancee could evolve into a Facebook-branded app or become part of the mobile Messenger app, which already shares a person’s location. Messenger, as it happens, is the result of Facebook’s acquisition of group messaging app Beluga last year.

Facebook’s main iOS and Android app will send users a push notification when one of their friends checks into a place nearby, but this does not seem to happen when a user simply tags a location in a photo or status, so most users rarely get these alerts or even know the feature exists.