Its FireChat app paved the way for chatting to friends without the need for the web or even a mobile signal. And now developers at Open Garden have built a small device designed to make these off-the-grid networks stronger. Called Greenstone, the egg-shaped gadget acts like a beacon, or booster, to help messages move around these so-called wireless mesh networks more easily. Its FireChat app paved the way for chatting to friends without the need for the web or even a mobile signal. And now developers at Open Garden have built Greenstone - a small egg-shaped gadget that acts like a beacon, or a booster, to help messages move around so-called wireless mesh networks more easily . FireChat launched last year and has been downloaded more than five million times. It takes advantage of a feature that launched in Apple’s iOS 7 called Multipeer Connectivity Framework (MCF). Android has a similar feature that works over Bluetooth. MCF lets you send messages and photos even when a person has no signal by creating what is called a wireless mesh network. Apple added to Multipeer Connectivity framework (MCF) to iOS 7. It creates what’s called a wireless mesh network that connects phones to each other. Instead of sending messages using mobile or data signal, the features lets users send messages to people in close proximity that are in Bluetooth or Wi-Fi Direct range - up to around 30 feet (9 metres). It does this by creating a localised network in which each phone becomes a node and the data is passed between nodes. Apple uses the framework for its AirDrop feature, for example, which makes it easy to send files and data to other connected iPhone users. However, there are limits to how far a message can travel in this way - at around 200ft (61 metres) - and Greenstone has been designed to solve this. When a user opens the FireChat app, they pick a screen name to start sending messages. Within the app there are 'chatrooms' with 'Everyone' and 'Nearby' options. The former will search for all users, while the latter option applies to people within Bluetooth and Wi-Fi range who are also using the app. This is particularly useful when on a plane, or the underground. It can also be used to save money on data plans, for example. The app creates a localised network in which each phone becomes a node, and the data is passed between nodes. Apple . uses the framework for its AirDrop feature, for example, which makes it . easy to send files and data to other connected iPhone users. These messages are sent securely, so the individual nodes can’t read them. Users can also send messages anonymously to avoid snooping, for example, because data is sent from app usernames, as opposed to mobile numbers. Elsewhere, because the feature doesn’t use an internet connection, it can’t be infiltrated by hackers. The 'Everyone' Setting allows people to send information further, however. It does this by bringing all its nodes . onto one network and relaying messages from one node to another until . it reaches the final recipient. In FireChat (left) there are 'chatrooms' called Everyone and Nearby. The former searches for all users, while the latter applies to people within Bluetooth and Wi-Fi range. It takes advantage of a tool used by Apple for AirDrop (right). This creates a network in which phones become nodes, and data is passed between nodes . Nodes . are simply a vehicle for passing data along a network. On a traditional . internet network any device that’s connected to the network is also . called a node. FireChat (pictured) has been downloaded more than five million times and is particularly useful when on a plane, or the underground . For example, if a network has a phone, tablet, two computers and a printer connected to it there are five nodes on the network. Each . of these devices has a network address which is used to uniquely . identify each one. This helps keep track of where data is being . transferred to and from on the network. However, there are limits to how far a message can travel in this way - at around 200ft (61 metres) -  and Greenstone has been designed to plus these gaps. Christophe Daligault, chief marketing officer at Open Garden told Daily Dot: 'The combination between [Greenstone] and the smartphones will enable a community, or a neighbourhood, or a hospital, or any other situation where they want resilient communication, even in the case of not having any connectivity.' It could also be placed in certain locations at music festivals, organised protests, football matches and other events where having large numbers of people can crash networks. Greenstone is still under development and only currently works with FireChat at a range of around 20ft (6 metres). Messages sit on Greenstone until another FireChat comes within range, and the device has a one-year battery life. It can additionally hold up to 1,000 of the most recent messages. Open Garden is now working with manufacturers to design and sell Greenstone and the timeframe will depend on these partnerships.
Greenstone acts like a booster for so-called wireless mesh networks .
It currently works with Open Garden's FireChat 'off-the-grid' FireChat app .
Both use an iOS feature called Multipeer Connectivity Framework (MCF)
Instead of sending messages using a mobile signal, the free app and gadget create a localised network where each mobile becomes a 'node'