The challenge centered around analysing aspects of smartphone logs for participants, over the course of a year. They derived social network information from these and wanted to study how these are embedded in time and space and why. The video below demonstrates the tool and explains how they used it.
The team custom designed, implemented and used a visual analytics tool to characterise spatial and temporal aspects of participants' social networks. The paper does not seem to be online at the moment, but its worth looking at for it over at Aidans page.