I'd like two features:
Multiple sender ids, this way I could have different ones for different groups I want to communicate with.
Save and restore wifi setting. I have a hotspot configured, it would be nice not to have to re-enter the network name and password when I turn tincan off.
Bonus feature request: set message expiration. So I can send a message, with an expire date/time, ie, meet me tonight, and tomorrow morning, the message goes away, so as to not clutter things up (and I don't have to say the exact date and time to meet or what ever).
TinCan could be very handy at something like burning man. If 1000 people were running it, it would propagate through that area very quickly (well, totally guessing, but I think that would be enough density).