While 99 per cent of London's black cab drivers are pretty trustworthy – there is always the 1 per cent of rogues that will try to take you on a merry trip around Olde London Towne in order to double the fare for the unsuspecting tourist or drunk.
No more! If you have an iPhone and use cabs on a regular basis, then the new London Taxi iPhone app is what you need.
It costs 59 pence and will ensure that you never get ripped off or overcharged by a cab ever again, providing you with an estimated fare for a ride in a black cab.
Developed by TFL planners
The app has been developed by two former Transport for London planners and the app bases its estimates using the TFL Taxi Tariff.
CabbyDavid of Twitter cab finding service @tweetalondoncab, has been quick to dismiss the app claiming: "If we were to go the routes [the app] suggested the fares would be double what they give."