A counter, a stall, or an event with visitors from everywhere
A front desk, a market stall, a stand at an event. Somebody arrives with a question and no language you share, and there is a queue behind them.
Scan and talk
Every room has a QR code. Print it, put it on the counter, and somebody points a camera at it and is in the room with you, in the language they picked.
They install nothing and make no account, which matters when the other person is not going to download anything to ask one question.
One room or several
Everybody who scans the same code lands in the same room and can read each other, which is fine for a stall and wrong for anything private.
A code can be either. Make the room private and everybody who scans it gets a room of their own, so the card on the counter works the way the bubble does.
So when something needs a conversation to itself, make a room for it and show that code instead. A room takes a moment to make and each has its own code and its own QR.
Where to put the code
The QR lives in the room, so you can show it on the phone in your hand. For a counter it is worth printing: on a card by the till, on the back of a menu, or on the sign somebody is already reading while they wait.
Open the QR in the room and save it as a picture. It has the code under it and a line saying what scanning does, so whoever prints it does not have to be told, and it is black on white with the margin scanners need. The link beside it is the same picture as an address, for a page or a post.
The six characters underneath it work too, typed into the home page, for a camera that will not cooperate.
Nothing is asked of them
No account, no app, no email, and no card. They give a name, which is not checked and can be anything, and pick what they read in.
It runs in the browser that is already on their phone, which matters when somebody is not going to install anything to ask one question.