The Website is very accurate, the main flight path from the US to
London Gatwick is right over Teignmouth/Dawlish, I was able to both
track the planes on the radar and see them from my window this evening
as they approached from Lands End and circled over Devon before
heading to Gatwick to land at 22:00 http://www.flightradar24.com/

Don't think I'll be taking up plane spotting as a hobby though,
alright for one night as a novelty!