Public channels versus private chats with people nearby

Use a public channel when you want to talk to whoever is nearby, and a private chat when the message is for one person. Flight Mode Chat offers both, and both work over Bluetooth Low Energy with no internet, no servers and no SIM.

How the app finds people

The app discovers nearby users automatically. You open it, and people around you who run it show up. Nothing goes through a server, because the app has none.

I build Flight Mode Chat, so read what follows with that in mind. I also point out the limits, since they matter more here than the features.

Public channels

A public channel works like a shared room. Anyone nearby who joins can read and post. That suits situations where you do not know who is around:

• A group of passengers on a long flight who want to say hello, swap seat-window photos or ask who has a spare charger.
• A hiking hut or campsite where several groups want to share a trail update.
• A queue or waiting room where people are curious who else has the app.

Because it is open, treat a public channel the way you would treat talking in a lift. Do not post anything you would not say out loud. Strangers can join, and I cannot promise who is listening in a room full of phones.

Private chats

A private chat is a conversation with one person. Use it for:

• Arranging where to meet a friend who is somewhere in the same building.
• Sending a photo, a voice note or a file that only that person should get.
• Sharing a contact with one person.

Messages are end-to-end encrypted, which means the content is readable by the two of you and not by someone who happens to be nearby with a phone. That protection applies to the message content, and it does not make a public channel private, since the whole point of a channel is that many people can read it.

Which one to pick

Situation	Better choice
You want to meet people nearby	Public channel
You are coordinating with friends	Private chat
You want to send a personal photo	Private chat
You are asking the room a question	Public channel

What neither can do

Both depend on being close to other people who also have the app. If nobody nearby has it, the channel is empty and there is nobody to chat with. Neither one sends SMS or iMessage, and neither reaches someone in another town. Text, images, voice notes, files and contacts all work in both, and the app runs on iPhone and iPad. Messages can be written in any language, though the interface is in English.

Related guides

If you want the plane-specific version, see chatting with passengers on a plane. For the privacy details, read encrypted offline chat, and for a broader overview, chat without internet on iPhone.