Getting into the wrong cab in Nigeria could end up in a kidnap which would cost your family a huge sum of money more than the agreed taxi fare.

To avoid this risk, many people now enlist the services of trusted taxi drivers who they call on whenever they need arises. But of what use is your loyal "cab man" if he is on the other side of the ever traffic-congested city of Lagos, when you need him?

It was a clear gap in the market for Easy Taxi, which like Uber uses a smartphone app and GPS technology to provide taxi services by linking up customers with a trusted driver who is nearby.

In Nigeria, Easy Taxi does not only recruits existing taxis, but ones that are carefully vetted with all their documents in order. Many will not pass the test.

The kidnapping of well-to-do Nigerians and expatriates in Lagos in late 2012 and early 2013 made a lot of people wary of flagging down unknown cabs which locals have dubbed "one chance," denoting the small, but terrifying, risk.

Consultancy Control Risks said Nigeria ranked third behind India and Mexico for recorded kidnaps-for-ransom in 2013, though last year it had been pushed down to fifth place by Iraq and Pakistan.

"People were being kidnapped in taxis, in public buses, so there was a big fear for safety," Easy Taxi Nigeria Managing Director, Bankole Cardoso said.

"We have a GPS tracker, so when a driver tells you 'I'll be there in five minutes,' you can actually see where he is on the map," Cardoso, 26, said.

Easy Taxi Nigeria, owned by South African mobile operator MTN, German startup incubator, Rocket Internet and Swedish technology firm, Millicom, uses an app to locate one of hundreds of taxis closest to the user.

Easy Taxi was founded in Rio de Janeiro, Brazil, pioneering online taxi services in Latin America and the brand has now spread to 33 nations around the world.

It fits right into Rocket Internet's strategy of taking successful e-commerce startup models and launching them in regions such as Africa, Latin America, Russia and parts of Asia.

The firm launched in Nigeria in 2013 in its ever-busy commercial hub, Lagos, home to 21 million people. It has since spread to the capital, Abuja, and gets a few hundred customers a day, Cardoso said.

Easy Taxi has also started services in two other sub-Saharan African nations, Ghana and Kenya. It has competitors in Nigeria, notably local firm, Afrocab, India's Taxipixi and Australian startup, Saytaxi.

The Easy Taxi app has proved popular with women and those traveling at night. A new service tailored for corporate clients has already signed up names such as MTN and Samsung.

Vivian Nwakah, director of a renewable energy start-up and an American of Nigerian descent, moved to Nigeria in 2013. She did not have a car and needed to find a reliable way to travel.

"The safety aspect was what was really important to me," she said.

The firm had to give smartphones to drivers in the startup phase. Now, drivers arrive armed with phones seeking work.

Cardoso declined to comment on revenues, but said the company plans to expand into other Nigerians cities soon.