I want to create an App where several people in close proximity with an android or ios phone can exchange a small amount of data with one person. So one person is the group leader, and (s)he transmits the name of the group to the other participants. I was thinking of using NFC but I have not been able to find out if iphones can transmit a value (it seems they can now read NFC tags - but I have not seen any examples of writing that data). I could use QR codes (so the leader shows the QR image and the others scan that image). Or I believe there are blue-tooth and wifi options. But I want it to be a very simple action - so turning on bluetooth/wifi and connecting sound like they are too long-winded. Any alternatives, suggestions?