Media playback is unsupported on your device Media caption How Michal Stencl created one of the world's biggest sat-nav companies in Slovakia

"When I was eight years old I got my first computer. It was a Commodore 128. I was lucky enough to realise at that point what I was going to do with the rest of my life," says Michal Stencl.

"I wasn't playing games on the computer. I wanted to make products for people. So I started programming," the 35-year-old chief executive and co-founder of Slovakia's Sygic tells the BBC from a wicker armchair on the fifth floor of his Bratislava office.

"When I was 13, I decided to write an operating system. Everyone laughed at me, because it was such a big challenge," Michal continues, a wry smile forming on his lips.

Today, the joke is on them. That early programming experience helped Michal to build a GPS giant, with turnover in 2013 reaching $18m (£10.5m).

Sygic has been installed on some 50 million phones, making it the world's most downloaded offline navigation app.

By the end of 2014, Michal hopes, that number will have doubled.

Image caption Michal Stencl turned down a life in Silicon Valley to create his sat-nav company in Slovakia

'First on the iPhone'

By the time he was 20 Michal had already written his own operating system called Qube OS - it led to job offers flooding in, including one from Silicon Valley.

However, he turned them down, opting instead to stay in Slovakia to be with the woman who would later become his wife.

Early forays into gaming and wi-fi systems were successful, but the real breakthrough came in 2004, when he saw opportunity in the fledgling field of GPS navigation.

Technology should save you time - that's why navigation is so popular Michal Stencl, Sygic chief executive

"I was looking for the next challenge. I felt that navigation might be the future. It was pretty difficult to start with, because I had no experience in that space, but that's what drove me," he says.

"I realised that to build something difficult is definitely your competitive advantage against the others."

The early mobile navigation environment was chaotic and cutthroat, a dog-eat-dog world of competing operating systems, he adds.

"When we started in 2004 there was Symbian, Linux, Windows Mobile - Maemo was the new flagship of Nokia - then iPhone and then Android.

"Nobody knew who was going to win the market. Our advantage was that we'd designed the whole app to be operating-system independent.

"The design we'd done previously - to create a multi-platform engine - helped us to be the first navigation app that was available on the new generation of smartphones.

"We were the first on the iPhone, and the second on Android."

Image caption Sygic's navigation app was designed to work on many different platforms, giving it an edge when the smartphone era dawned

Future connectivity

But the GPS "ecosystem", as he calls it, is still a complex environment, divided into three distinct but sometimes overlapping worlds - personal sat-nav devices like TomTom and Garmin, smartphone apps like Google Navigate and Waze and finally the built-in navigation systems found in expensive cars.

"We believe that ultimately this eco-system will consolidate and merge."

TomTom and Garmin devices are already on the way out, and instead you should expect to see greater connectivity between your phone and your car, he argues.

"On one hand, smartphones are going to be your personal device, where you're going to plan your route.

"But they'll use your car's sensors, its loudspeakers and its dashboard screen to navigate you," he explains.

Sygic already offers a glimpse of that future connectivity. Its head-up display projects your route from your smartphone onto the windscreen at night.

But for now, Michal is primarily concerned with maintaining Sygic's market dominance as dozens of new navigation apps, paid and free, crowd Google Play and the App Store.

Image caption The marketplace for sat-nav is now crowded and complicated offering different products at different prices

From tasters to paying customers

At present Sygic offers users a free taster of the app's premium version for seven days.

This includes 3D maps with a shimmering graphic interface, turn-by-turn voice-guided navigation, speed-limit warnings and a junction view with lane indicator arrows for tricky intersections.

After seven days the app reverts to a free version, which people can use indefinitely but without the bells and whistles - no lane guidance, no turn-by-turn instructions and no 3D.

The idea is that users will then pay to revert to the premium version depending on the coverage they want.

What is it like to be an entrepreneur in different parts of the world? The BBC's global team are talking to people starting their own businesses around Europe. What battles do they face to make their mark and make money? Read more My Business stories

Sygic is coy about how many trial users become premium users. But the firm now employs over 110 people and Michal has a Porsche in the company garage.

"I bought it for the kids," he says, somewhat unconvincingly.

Sygic's diversifying too. Special apps are already available for trucks and taxis - and bicycle navigation is currently in development.

Outside the world of vehicles, Sygic's family locator offers what the company describes as "real-time tracking of your family members", allowing a parent to follow their child's progress to school, or a spouse as they walk to the shops.

It sounds rather sinister. But perhaps it is inevitable as all of us become online, all the time.

"I believe the future is in saving time. Technology should save you time. That's why navigation is so popular," Michal says.

"If you work out how to save your customers more time in things they use on a daily or hourly basis, you're going to win that market."