New app shows who and where you are

While developing new technologies for the classroom, Blackboard co-founder Michael Chasen saw firsthand how frequently students use their mobile devices to keep track of each other. Now he has raised $12.75 million for a new project inspired by the desire to know exactly where your friends are. SocialRadar , a company headquartered in Washington, DC, has developed an app that shows the locations of nearby classmates, colleagues, and even strangers with similar interests. Due to be launched in the fall, it will be available for the iPhone and Google Glass .

“The goal is to able to walk into a place, see who is around, and know everyone’s name,” says John Fontaine, vice president of the new enterprise’s Google Glass department.

A physics student attending a conference—or a professional physicist, for that matter—could upload a photo, as well other information such as her affiliation and specialty. Other attendees could then call up a flash card with that information and see the student’s location on a map. Colleagues popping in and out of talks could thus search for each other and for people they don’t already know working in similar research areas.

Whether someone wants to be tracked down is a different story. Apps like SocialRadar inevitably raise privacy concerns—especially in the wake of recent revelations. News about the NSA’s secret tracking programs, for instance, have spurred national dialogue about information gathered from mobile devices.

“Our goal is to make it clear to people what their privacy options are right up front,” says Fontaine. Users of SocialRadar select how much information to make public, from full biographical details to complete invisibility. But the app will also import information from other social networks such as Facebook and Instagram, showing friends who do not have the app but who have tagged posts on those sites with location information. How long the company will hold the information it collects has not yet been finalized.

SocialRadar is by no means the first app to ask its users to give up some privacy in exchange for information about people’s locations. A slew of products allow singles to rendezvous with each other or businesses to offer coupons to customers in their areas. Some even track traffic by calculating how quickly the phones on a stretch of road are moving.

The growing sophistication of mobile devices enables this trend. Smart phones equipped with GPS can now determine their positions fairly accurately. App software pings phones for this information and uses a bit of linear algebra to calculate how close people are to each other. Software can also now draw virtual boundaries around points on a map. These become “geofences” that send alerts when people cross them.

“People have been talking about these ideas for awhile but until recently the technology for doing them hasn’t been generally available,” says Naomi Morita, chief technology officer of Locaid . The San Francisco-based company helps online gambling companies track their users to comply with regulations.

Another San Francisco-based company called Life360 employs geofences to help parents monitor their kids. When a phone equipped with the app crosses a geofence surrounding an important location—a school, for instance—the parent is automatically notified. A mother can also pull up a map and follow the movements of her child as he walks home from school or takes the family car out for a spin.

Power struggles

One challenge for these apps, says Life360’s chief technology officer Alex Haro, is the cost of playing this Marco Polo-like game of call and response with a phone. The more often the device is pinged, the better its location can be tracked. But every inquiry consumes some of the processing power of the computer making the request and, more importantly, drains the battery of the phone replying.

To illustrate how difficult striking a good balance can be, Haro cited Highlight , an app that, like SocialRadar, reveals the locations of people nearby. “They made a big splash at South by Southwest [an annual music, film, and interactive conference and festival held in Austin, TX] and were then instantly forgotten about because they murdered your battery,” says Haro.

One way to spare the battery is to adjust how often pings are sent. A phone that has not moved recently might be left alone for a while. But this approach risks missing movements when the stillness is finally broken.

Another strategy uses the complementary technologies that phones can draw on when calculating their locations. GPS provides the most accurate measurements but also drains the most resources. Switching to information gathered from cell phone towers or WiFi networks can be kinder on a battery and provide coordinates that, while less precise, can still be useful when exact knowledge is not needed.

SocialRadar will be putting its own battery manager to the test on a new platform: Google Glass, a device worn much like a pair of eyeglass. Instead of lenses, it features a transparent block just above the right eye that serves as the display, creating a screen that, because of its closeness to the eye, looks like a 25-inch television viewed from eight feet away. Voice commands and flicks of a finger across a touch sensor near the temple can call up SocialRadar and cycle through images of people nearby.

Though Google Glass comes equipped with a video camera, SocialRadar does not plan to add the ability to recognize faces to its app. Google has banned face recognition from its device, citing concerns about privacy.

For its initial release, Social Radar will target places where people congregate in high densities: college campuses, events, and specific metropolitan areas. “We want to build the network in a way that it spreads virally,” say Fontaine.

Fontaine hopes the app will grow and evolve, providing a platform on top of which other products that need location information can be built. He notes that Twitter started off as a simple message service that became more complex as hashtags and search functions and other features were tacked on over the years. Says Fontaine: “If we can solve the ‘where are you now’ question, I think we will have created one of the great information services out there.”

Devin Powell is a freelance science writer based in Washington, DC. His stories have appeared in Science News, Wired, US News & World Report, and other outlets.