iOS lets you share wifi passwords with someone else around you if they are trying to connect. I _think_ it uses your AirDrop privacy settings so for most reasonable people it would only work for people in their contact list.
The only thing I don't love about it is, there's very little user feedback. The person requesting just goes to the wifi password prompt and hopefully this generates the notification for one of their contacts.
Nice when it magically works (you go to wifi, and then someone in the room is like "Hey, dcdc123 wants the wifi password" and you are like "yep," and then it's all sorted), annoying when you are intentionally trying to use it with one particular person.
It would be nice if it showed something like "looking for contacts" "found <NAME>" etc etc.