As part of our location-sharing research, we've been looking at how people use location-sharing and the interaction design elements that affect their attitudes and behaviour by both studying existing services, and building on top of them.
We’ve been taking a ‘performative’ view on check-ins on foursquare, and explore how these specific design elements facilitate emergent, and sometimes conflicting, social norms (not) to check-in. Read more in our MobileHCI’11 paper here.
Interested mostly in gamification elements? Shorter paper ‘Gamification and location-sharing: some emerging social conflicts’ presented at the Gamification workshop at CHI’11 here.
In the mean time, our foursquare check-in apps PhiSquare (check-in via QR codes) and Pic-In (check in by taking a picture - 3rd prize in this year's Ericsson app awards!), are still downloadable as Android apps.