Google wonât approve  any apps for its head-worn Glass device that use facial or audio recognition to identify and learn more about the people around you. There are other ways to accomplish this, though, such as by looking at the location information in social network updates.
This is the tactic that SocialRadar, a Washington, D.C.-based startup, will employ with its free app of the same name. The company released its first app for the iPhone on Thursday, and plans to follow it with a Google Glass app in the coming weeks. An Android app will also be available shortly.
Created by Michael Chasen, who cofounded the education tech tools company Blackboard, SocialRadar lets you set a âradar rangeâ around yourselfâ"25 feet, five miles, or the entire United States, for exampleâ"in which it will sniff out people you know, letting you see whoâs nearby and how youâre connected. It can tell you, for instance, how many of the people around are friends of yours (either within the SocialRadar app itself or on social networks that youâve connected to your profile), how many people are friends of friends, and which of these people went to the same college or high school as you. Then it can direct you to these people; if theyâre also using the app, you can send them a message.
SocialRadar is the latest to attempt to use social and location signals to match up people, which has already proved a tough market for a number of startups like Banjo  , Highlight  , and Sonar (Highlight is still around, but Banjo has since switched directions and Sonar closed up shop). Like these companies, SocialRadar is focusing largely on the smartphone market for now, which makes sense since so many of us carry them around.
But by also paying attention to the growing market for wearable devices, and Google Glass in particular, SocialRadar may be in a better position to gain users than its predecessors.
âItâs a great form factor for this type of technology,â Chasen says. âImagine youâre wearing Google Glass, you walk into a room, a card appears and says, âYou know 10 people in this room.ââ
Since the Glass app isnât yet available, I tried out a preview version of SocialRadar on my iPhone this week to get a sense of what SocialRadarâs going for. I connected the app to several of my social network profilesâ"Twitter, Facebook, LinkedIn, and Instagramâ"so it could sort through those for friendsâ location check-ins, as well as to my iPhone contacts list. I also left my SocialRadar profile visible to anyone else who was using the app (at the time, it looked like there were under 100 of us) so they could see who and where I was.
Although there werenât many people near me, I did get some hits. The app indicated there were 11 friends nearbyâ"10 of them scraped from Foursquare check-ins ranging from 9 minutes to five hours earlier, and one of them being Chasen, who I âfriendedâ within the app. There were also 33 friends of friends, social network connectionsâ friends who were also early users of the SocialRadar app and left their profiles open to everyone.
I could see a few more details, such as that one person around me (though in this case, several hundred miles away) went to my college, three also live in San Francisco, and one also enjoys the tunes of Lauryn Hill. Had I wanted to meet one of these people in person, SocialRadar could show me where they were on a map or I could use a compass view that would help me walk in their direction.
You can also instruct SocialRadar to alert you when certain people are nearby. This can be as simple as telling it to ping you if a college buddy is in the area, or as complex as asking it to let you know when, say, someone who went to your high school and works in the entertainment industry is within half a mile.
While SocialRadar regularly looks for new check-ins from your social network, you get much more accurate location data on friends who actually use the app because the app can more often update your location via GPS. Social check-ins, on the other hand, can be several hours old.
On Glass, Chasen believes SocialRadar can be even more helpful since it offers alerts right in front of a userâs face. He says the SocialRadar Glass app, which the company is still working on, shows you how many people are available around you and their basic connections to you (friends, friends of friends), and lets you choose which group of people you want to see. You can tap the touchpad on the side of the Glass headset to get more information on a person, or to navigate to where they are.
For most people, though, getting this kind of data on your face could take years, if it happens at all. Glass is still an extremely niche product: itâs slated to be released sometime this year, but is still only available by invite and has about 10,000 users.
And the functions that developers can offer through Glass are still pretty limited. For instance, Chasen says, there isnât yet a way to create SocialRadar alerts on the device.
âItâs kind of a little painful,â he says. âItâs getting there, though.â