In recent days, instant messengers have become extremely popular. 70% of smartphone users in Russia conduct their correspondence using instant messengers, and only a third of the audience prefers SMS to other methods of chat correspondence. WhatsApp, Wiber, Telegram are the most popular and in many ways similar clients. But the guys from Open Garden Inc (one of whom is a graduate of the Faculty of Mechanics and Mathematics of Moscow State University) decided to look at the situation in the world differently, and created FireChat. The messenger, which bypasses cellular networks, pioneering communications within the entire city. Offline messaging. The first thought that comes to mind is of course Bluetoch. It would seem nothing special. There is more than one application that is able to set up a chat via Bluetooch. Even when Apple started AirDrop, some users came up with the idea of chatting using notes, sending them to each other. But FireChat is different. The client can transmit a message from the interlocutor to the interlocutor over considerable distances. This is achieved in the following way: a network is created from all devices on which this messenger works. The message travels by the shortest route, from one phone to another, until it reaches the goal. The developers claim that if 5% of the city uses their application, then the coverage area will cover the entire city. All messages are encrypted. This means that only the sender and recipient will see the text, not the intermediary devices. To use the application outside of cellular networks, you need to enable Wi-Fi and Bluetooch on iPhone. There are five main tabs in the application interface: Chat rooms – the most popular public chats at the moment; Messages – a list of all your dialogs; Contacts – contacts from your address book (those who have not installed FireChat have a button “Invite to FireChat”); Find – search for users; Yet. The last tab contains your profile, settings, help, and popular general chats. Each chat has a slider at the top, when you switch to the “Subscriptions” field, messages of only those users you follow will be displayed. You can also like messages (how can it be without it). The page of each user displays his subscriptions, subscribers, messages that he left in public chats. In conclusion, I would like to note that the beauty of the application is not in general chats and a variety of topics for communication, but in the fact that there is an opportunity to communicate without a cellular network. This can come in handy, on the plane, at a match, during natural disasters, when the traffic runs out, etc.