Your phone is a pocket-sized supercomputer, but when you don't even have cellular coverage to send a text message, it feels more like a paperweight. goTenna is a portable RF antenna that lets you communicate even when your phone has no service whatsoever. You won't be posting selfies to Instagram or catching up on your Hulu queue, but goTenna lets you exchange text messages and GPS coordinates with other goTenna users who are within range--and that range could be a mile or so in a city to a whopping 50 miles if you happen to be standing on top of a mountain.
goTenna is a flattish device a little under 6 inches long, 1 inch wide, and only half an inch thick. To turn it on, you extend the antenna another 2 inches, and an LED lights up to show you it's working. goTenna connects via Bluetooth LE to your iOS or Android device. So you use the app to tap out messages, which the goTenna device broadcasts over low-frequency RF, which is what gives it such great range. (It uses the 151154MHz end of the spectrum, where there isn't much crowding, either.) Since only other goTenna devices can receive the encrypted signal and send it to the app, goTenna is sold in pairs.
Shout it out
Using the app, you can send private messages to your contacts, or send a "shout" to every goTenna that's in range. Users can opt out of receiving apps from people they don't know, but if you send your blast as an emergency message, every goTenna that hears it will automatically pass it on the person's phone. goTenna's cofounder and CEO Daniela Perdomo got the idea for the product during the aftermath of Hurricane Sandy, when a quarter of all the cell towers were down, and neighbors came together to assist each other. So emergency mode sends out a call for help to everyone who can hear.
You'll get a delivery confirmation when your message goes through, and if it doesn't, goTenna will try again a few times and then tell you the message failed. You can tell it to keep trying, or move to another spot first, where goTenna's signal might be able to travel farther.
You can also use goTenna to let people know your location. Your phone's GPS actually works whether there's a cellular connection or not, but without a data connection, all you'll see in most mapping apps is a blue dot on an empty map. goTenna's app includes a free vector map of the entire world, and you can also download free map packs for the places you'll be traveling, to get more granular detail, down to the buildings on each street.
Good to go
So while goTenna would be a handy addition to your emergency kit, its ability to find and talk to your friends when the cell network is failing you would be great in a lot of situations. A group of pals toting goTennas could keep in touch at music festivals, on camping trips, while skiing, or even to avoid data roaming when traveling in foreign countries. The goTenna device comes in four colors to tell them apart, and a sturdy webbing loop lets you dangle it from a backpack, a hat, or even a tree to get better reception. It weighs only 2 ounces, and it's weather proof.
You do have to charge goTenna, via micro-USB, but it should last for two or three days of regular use, and if it's stashed in your emergency kit, it can hold a charge for up to a year and a half. While so far goTenna's app is focusing on text chatting and location sharing, goTenna's SDK will let other developers enable their apps to send data with goTenna, effectively letting them work without cell service too.
goTenna is taking preorders starting Thursday, with devices sold in pairs for $150, which is half the price goTenna will sell for when it ships in late fall. So it's not exactly an impulse buy, but it's cheaper than a satellite phone--and when you really need to communicate while stuck off the grid, goTenna's capabilities will seem priceless.