The Lord Mayor's Show is the world's oldest, longest and most popular civic procession. It fills the whole City of London and is attended every year by several hundred thousand spectators.

This is the official app for the Show. It is small and neat and designed to help without getting in the way.

It has a timetable, a map of the area and a guide to the procession. If you're standing by the route, it will use the iPhone's GPS sensor to tell you which floats are passing by, offer a brief description and a web link.

It also provides a basic messaging service. We will have people posted at Guildhall, in the police station and on the route, and app users will be notified immediately of any danger, diversion or change of plan.