蜜芽传媒

A teenager from Tonyrefail has invented an app to stop people from sleeping through their tube stop - despite never having lived in London.

Dafydd Jones, 16, invented the "Doze" app after his brother -- who does live in London -- fell asleep after a night out and missed his stop.

To get around the lack of GPS underground, the app uses wifi signal to determine where on the tube map you are.