London is a big city with a rich history, containing a population of more than 13 million people. I fell in love with it when I worked there as a motorcycle dispatch rider for more than 15 years, and it's a love affair that continues today. Even though I haven’t lived in London since the late '90s, I still know where to go on a big night out. But so do a lot of other people who don’t have the same understanding of the city -- all it takes is a smartphone with the right apps.