Useful official and operator apps for tickets, live departures, journey planning and disruption checks. Airport pages link here instead of duplicating app-store links.
National Express
For airport coaches, use the National Express Coach app for iPhone or Android. It supports journey search, booking, stored tickets and live coach tracking. See also the official timetables.
TfL Go
For journeys inside London, TfL Go for iPhone and Android provide live Tube, Elizabeth line, DLR, London Overground and bus information. Particularly useful for Heathrow and London City, and for onward travel after reaching central London from another airport.
National Rail
For live train times, platform information and disruption across the UK rail network, use National Rail. This is the common reference for rail journeys involving Gatwick, Luton, Stansted and Southend.
Luton DART
For the station-to-terminal link at Luton, use the official Luton DART site for live service information, fares and tickets.