FireChat is an iOS and Android app that enables smartphone users to chat even without a cellular or internet connection. That’s why it bills itself as an “off-the-grid” messaging app.
FireChat is being used by the protesters in Hong Kong, to ensure that they can continue to communicatte if the Internet is blocked.
It can also be used to chat over the internet, via its “everyone” mode.
The app was developed by a San Francisco-based company called Open Garden. They say FireChat is ideal for situations where Wi-Fi and mobile phone coverage aren’t available, such as on the subway or in the wilderness.
In “nearby” mode, the app uses Bluetooth to connect to nearby phones that have the app installed. When the iOS app was first released in March, Open Garden wrote on its blog that the nearby mode works best within nine meters of your location. The description for the Android version of the app in the Google Play store says nearby mode can be used up to 60 meters away. However, users can connect over longer distances via daisy-chaining with other users, thus forming “distributed” or “decentralized” network. These decentralized networks have the potential to replace conventional internet access — see this article for more information.