Flocks of confused, gawping tourists notwithstanding, it's typically pretty easy to find any address in Manhattan, where streets are aligned to a grid. But in most of the world, this isn't the case. Indeed, nearly 75 percent of the world, especially in developing countries, lacks a precise street address. This can pose an enormous challenge, and not just for mail delivery. Consider aid organizations sending food and water to people who desperately need it, or firefighters rushing to the site of an emergency. It's critical that they be able to easily find the place they're going to.

That's where what3words comes in. The London-based company, founded by Chris Sheldrick and Jack Waley-Cohen in 2013, uses a novel approach to make locations around the world easier to find.

Here's how it works: what3words' global map divides the world into 57 trillion 9-square-meter areas, and assigns a unique, three-word name to each square. For example, the White House sits at engine.doors.cubs, while the Taj Mahal can be found at according.gloom.broads. (By virtue of their size, places like these actually have more than one set of names associated with them.) Just type in the three words on what3words' site and it shows you where to go. Or vice versa, if you want to learn the words; just pick a spot on the map or enter a street address or latitude and longitude coordinates.

"The idea is that it's more specific than postcodes, which were invented when posting letters was the main form of communication, and simpler than GPS coordinates, which are too complex for the average person to remember," wrote Jeff Parsons in the Mirror.

An algorithm generates each three-word phrase. It filters out profanity, avoids homophones to reduce the chances for mistakes when an address is spoken (hear vs. here), and safeguards for slip-ups with singular and plural words. If you accidentally type engine.door.cubs instead of engine.doors.cubs, you'll get a location halfway around the world — your mistake should be obvious. The system comes in nine languages, including Portuguese, Swahili, and Turkish. It's available on its own as an app, but is also integrated into an array of other companies' and apps' mapping systems.

Poor address systems are a widespread problem, and the implications for people without an address are vast: "This cohort of 'unaddressed' can’t open a bank account, can’t deal properly with a hospital or an administration, let alone get a delivery. This is a major impediment to global development," Frederic Filloux wrote in Quartz.

Shipping companies have been aware of the problem for quite some time. Sheldrick, the company’s CEO, says that UPS estimates it could save $50 million a year if its trucks drove one mile less every day. Getting lost less would certainly help. “That's an incredible statistic that we're trying to fix," he says.

The concept for what3words arose from a gripe Sheldrick had in his previous job as an events promoter: he consistently had trouble directing musicians to the proper entrances at large venues. "In that instance, you can't just give a generic address," Sheldrick says. A mathematician friend of his came up with the concept of dividing the map into squares with easy-to-memorize names.

It was initially a challenge to get companies on board: "A lot of people are scared to take the risk of being first," Sheldrick says. But what3words found a supporter in Navmii, a London-based company that makes a navigation app for smartphones. Navigation-tech companies, says Sheldrick, field many complaints from users about GPS glitches, which often arise from incorrectly tagged locations. "That's been our strategy since day one: Find the organizations that really struggle with addressing, so that they become our advocates," Sheldrick says.

What3words is now used in more than 170 countries across every continent except Antarctica. In addition to navigation companies, its customers include NGOs, online retailers, and travel companies, which pay to integrate what3words into their internal mapping systems. The World Bank has used what3words in Tanzania to track and maintain public water access sites throughout the country. The company has received $5 million in funding from investors such as Intel Capital, reports TechCrunch, and last year, it won the Innovation Grand Prix at Cannes.

It's key that the three-word phrases are easy to memorize, because many of the people who are served by what3words' system don't have a smartphone to look them up. Instead, Sheldrick says, once they've been given their address by an aid worker, or a neighbor who has a smartphone on hand, they can simply make note of the phrase for future reference. He gives the example of Rocinha, a slum in Rio de Janeiro, where residents are beginning to use what3words as an alternate address system to receive mail.

Next up, says Sheldrick, is adding more e-commerce and transportation companies as customers. The company will also soon finalize its first partnership with a national postal service.

Another technology what3words is keenly interested in: drone delivery. There's been talk for years of companies like Amazon using drones to ship packages, and most recently, the drone manufacturer Zipline has contracted with Rwanda's government to deliver medical supplies. It's an ideal application for what3words, and one that may prove to be quite lucrative, Sheldrick says: "People will have to start thinking far more precisely about location when it comes to drones dropping things."