Daniela Perdomo first conceived of goTenna when she was volunteering for Hurricane Sandy relief efforts back in 2012. She saw that following the storm’s destruction, even emergency responders were having trouble communicating.
Using a device-to-device mesh network, she created a product that let people text and use GPS on their phones without a cell signal or internet connection.
This summer, with Perdomo as CEO, goTenna released the goTenna Mesh, an upgrade from the original device, creating a consumer-ready mesh network. The new device lets users privately relay messages through other goTenna users to overcome distance limitations. The more people in your network, the greater your range.
In addition to being used by military operators and first responders, the devices also have a following among travelers and outdoors enthusiasts. The company raised $7.5 million this year, led by Union Square Ventures.
This article originally appeared on Recode.net.