http://www.flytecomm.com/cgi-bin/trackflight
Stick the full callsign into the "Flight Identifier" box eg MON712G BMI3513 etc
Alternatively put the arrival airport ICAO code into the A"Arrival Airport" box, so in this case LEMG (Not AGP!)
It only works for flights originating in the USA, Canada, the UK, and Ireland. You seem to be able to get spurious info from Iceland and some South American flights too, but the rest of Europe is a nono unless the flight starts in the UK or Ireland.