Airport calls for "Friends of Bill W" is an interesting use case for bitchat. I could see that finding actual use, and for the good.
For those not acquainted with this subculture:
People in recovery often find airports challenging ā this is a place where one is socially permitted to drink at any hour of the day ā and call for help there to remain sober. An anonymous location-based, p2p chat app fits the bill.