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 .
Multipeer Connectivity Framework 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 Greenstone ( MCF ) Instead of sending messages using a mobile signal , the free app and gadget create a localised network where each mobile becomes a 'node '