FireChat, a popular off-the-grid messaging app from Open Garden, has been lately upgraded to include a new feature that will allow users to chat in groups even in the absence of a data plan or an Internet connection.

Available for Android and iOS, the app uses the innovative approach of sending messages through Bluetooth and Wi-Fi that are installed in one's smartphone. Makers of the app believe that FireChat could one day tie together numerous devices that have built-in radios and that it could allow users to be online without the need to spend a price in order to gain access. Other areas that could benefit from the new approach include those that are remotely located or those that belong in a disaster zone where there is no Wi-Fi or cellular signals.

Open Garden adds that the conversations that are exchanged through the app are encrypted in the sense that they can't be easily hacked or be shut down by governments that don't support free speech.

"FireChat's announcement that it will seek to provide end-to-end encrypted messaging is a positive step for privacy," said Richard Tynan, a technologist at Privacy International, in a statement to BBC. "However, it remains to be seen whether the quality of these implementations actually lives up to the claims. It is vital, therefore, that claims about security can be verified and tested independently."

According to Open Garden, so long as 5 percent of the city's population is using the service, it will be able to deliver messages sent by the users at an average delivery time of 10 to 20 minutes. The more users are using the app, the stronger the network becomes. This can be referred to as "self-healing networks."

"Unlike traditional networks or Google and Facebook's endeavors to expand the reach of the Internet via satellites, drones and balloons, our new networking model does not require capital and scales up infinitely," said Open Garden.

With six million users currently using FireChat, Open Garden aims to go further by making the technology available to companies that are into the development of apps and devices.

"This innovation paves the way for the next evolution of the Internet: networks created by the people, for the people," said Micha Benoliel, CEO and co-founder of Open Garden.