You can reach billions of people in seconds with a blog post from an iPhone, but as soon as you go somewhere without WiFi or cellular coverage, it's like you're suddenly decades in the past. Your smartphone becomes a glorified camera or Game Boy, assuming you have games that work offline.

In late October 2012, Hurricane Sandy took out cellphone towers and power lines, turning large parts of the New York City metropolitan area into a huge, pre-Internet, pre-cellphone dead zone. It spurred siblings Daniela and Jorge Perdomo to create goTenna, a device that attaches to your smartphone to enable communication off the grid -- or, as the case may be, when the grid's suddenly not there anymore.

Like a storm, goTenna happened quickly. Daniela was living in New York City when Sandy hit on Oct. 29. By February of the next year, the entrepreneurial pair had already developed a working prototype of goTenna and the beginnings of a startup, with Daniela as CEO and Jorge as CTO. That's an incredibly fast turnaround, but Jorge had already been thinking in that direction, Daniela already had startup experience, and the siblings shared a background that primed them for their jump into entrepreneurship.

Jorge and Daniela spent most of their formative years living in Sao Paulo, along with stints in Miami, Mexico City and Buenos Aires, as their father was a self-made CEO of a Latin American multinational.

Both Perdomo siblings were interested in technology early on, but in different ways. "My interest in technology is more socio-cultural, which I believe is in some ways the result of growing up in Latin America where the technological divide -- like all other kinds of inequality -- is so much more pronounced," Daniela explained to Latin Post.

"Jorge has always been into technology from a how-it-works perspective, building tesla-coils and whatnot with our dad," who also happened to be a trained engineer, according to Daniela.

The two went to prestigious colleges in the U.S. -- Daniela to Tufts and Jorge to the University of Pennsylvania -- and afterwards, Daniela began working at software startups, eventually landing in New York City. "Jorge had the initial idea," said Daniela, "and he came to me because I was the only person he knew who worked in tech startups!"

But necessity or not, it was a perfect pairing. "I think he recognized even before I did that we have pretty complementary skills -- he's very systems-oriented and hyper-logical, where I'm more story-oriented and psychological. Those are good skills to have for a CTO and CEO, respectively."

You could say goTenna began before Sandy hit, when Jorge had a flash of inspiration earlier the same year. He was at a music festival, frustrated that he couldn't reach his friends on his smartphone. The local network was just too clogged beyond capacity with others trying the same thing.

That was the origin of goTenna, "the first 'aha' moment," as noted by Daniela, who admitted she wasn't on board with his idea at the time. "When he explained it to me, in the summer of 2012, I wasn't hugely interested in it, and didn't really consider what other uses, beyond big events, such a technology might have."

"Then came Hurricane Sandy that October." That's when a significant use-case for Jorge's idea literally hit home.

"As I sat there in the dark, trying to get in touch with people to make sure they were okay," she recalled, "and failing with some because they were in a disconnected part of the city -- I realized it was crazy that we have these supercomputers on us that don't enable us to communicate in times when we need to most."

GoTenna cuts out the network middleman, instead connecting with smartphones through Bluetooth and using long-range radio waves to send messages and location information directly to other goTenna-enabled devices. Furthermore, no middleman means no subscription fees, as satellite phones -- the only current competing technology besides walkie-talkies -- require.

While the device and eponymous startup was spurred into being by an emergency situation, the Perdomo siblings saw useful applications like music festivals, skiing, and hiking as well. And as more people hear about goTenna, unforeseen uses for goTenna are coming out of the woodwork -- along with more prospective customers.

"I think we're most proud of the fact that goTenna can be used in ways we've not even thought of," Daniela said. "It's great for people who love to do outdoors activities in the middle of nowhere... or for those who love to travel internationally but don't want to pay hefty roaming fees," to keep in touch with their traveling partner nearby.

"Many of our customers come from remote or rural areas like Montana or Hawaii, where they don't get great cell reception," Daniela continued. "They'll use goTenna on a daily basis to communicate with coworkers, family members, friends because there's literally no other option!"

Speaking of the Montana set, goTenna is encrypted end-to-end by design. Since it literally doesn't pass through any intermediary, creating its own closed network between devices, it could become a popular tool for the (hyper) privacy-conscious in the age of digital surveillance.

But you'd never guess the goTenna's off-the-grid disposition from the look of their device.

(Photo : goTenna)

While it's water resistant and rugged enough to be strapped onto a backpack for a weekend in the wilderness, goTenna is lightweight, pocket-able, and made with an attractive aluminum and nylon design. Packing its BluetoothLE, processor chips, an LED status light, and an antenna into a thin wand, goTenna looks a bit like if Apple spent time and energy developing the perfect meat thermometer. In the best way.

Daniela said finding the balance between utility and form was the hardest part. Theoretically, she and her brother could have designed it with a long unwieldy antenna to maximize goTenna's range.

"But we didn't want to sell a giant product that wouldn't be easily portable," Daniela explained, "so we are literally operating at the limits of science with our device." Check out GigaOm's technical report for an explanation of why that's true (warning: it heavily involves frequency specifications and fractals). When it all boils down, the under six-inch device's range is ideally up to 50 miles, "and reliably many miles of range in most real-life scenarios," said Daniela.

Right now, Daniela and Jorge are focused on bringing goTenna -- the device and its complimentary messaging and location app -- to market. That'll happen later in the summer, according to Daniela, and goTenna is accepting pre-orders in the lead-up -- at a price of two for $150.

The Perdomo siblings have already lived up to a prediction their father made when they were young. "He believed my brothers and I would have careers that involved work or even industries that didn't exist yet," said Daniela.

But if goTenna does become its own platform for developing new ways to connect people without infrastructure, they could actually surpass that prophecy -- by creating, themselves, an industry that doesn't yet exist.

Daniela thinks goTenna might be the beginning of something bigger, especially when programmers start tinkering with the software development kit (SDK) they've made for it. "The potential of it becoming a platform, via our SDK, that other people build on is really exciting, and means the possibilities are kind of endless."

As far as big possibilities, Daniela still has her eyes on the technological divide she saw growing up in Latin America. GoTenna might soon be a step towards connecting the hardest-to-connect: "We're excited for future products that will bring basic communication to totally disconnected people and places where smartphones and cell towers aren't ubiquitous."

"I think technology becomes truly revolutionary when it's accessible to all kinds of people," Daniela said. "We're definitely thinking beyond the developed world."