Thanks for the quick response! I personally liked #24, as it reminded me of an ninja but that probably won't work for this project. ;)
#27 is closest for the mobile app. We're debating whether the two people "holding hands" would be cleaner and still maintain the infinity shape. Not sure if this look would be too feminine for a college male audience. Also, while we all like incorporating the infinity, it isn't telling an audience that its a mobile app, used for communication, etc. We'd have to incorporate some other element(s) that conveys these things.