Hailo - cabbies and capitalists

It's hard to think of many UK tech firms that have gone global in recent years - but a business started by three entrepreneurs and three London cab drivers may well be the cream of the crop.

Hailo, a mobile phone app which allows you to virtually hail a cab, has unveiled a major new investment and plans to launch in New York and Tokyo.
The app was launched in London in November 2011. Its success was by no means guaranteed, as at least half a dozen similar ideas were already on offer to the capital's taxi and minicab users.
I've been chatting to Hailo's chairman, American entrepreneur Ron Zeghibe, and to Russell Hall, one of the three cabbies involved from the start, about what really made a difference.
Ron, who's spent 20 years outside the US launching various businesses, explains that he and two other entrepreneurs had come up with an idea for a taxi app. But they realised that the key to success would be an intimate knowledge of the cab trade, and that's when they met up with Russell Hall and his two colleagues.
The cabbies had already been operating their own web-based service, Taxilight, for a couple of years but wanted to move it on to a new level. The two groups clicked.
"We sat in a cafe in Charlotte Street," says Russell, "and chatted for hours on end about the moans and groans of cabbies and customers, and after endless cups of teas and rounds of toast we shook hands on a new concept."

The key appears to have been making the Hailo app work first as a useful tool for cabbies, even before it was launched to consumers. Ron says what they came up with was "a working tool for drivers, with a whole series of aspects which made their working day more useful and effective".
This meant that when they did launch to customers, they already had hundreds of drivers signed up - so when you clicked to request a taxi there was a fair chance of getting one.
Today, more than 10,000 London cabbies are using the app - that's probably at least half of those who are actually out on any one day.

Tell me about your favourite apps in your mobile phone. 200 words