I flew out of LHR today, having left the free versions of both apps installed on my phone. Neither of them provided gate information before it appeared on the airport screens. Even by the time I had boarded the aircraft, neither app had notified me of the gate number.

After arriving at my destination and connecting to a WiFi network, only 'The Flight Tracker' provided a notification of the delayed arrival time; although to be honest I'm not too bothered about post-flight information. I'll leave the apps installed to see how things go on the return journey, but based on my (admittedly limited) experience today, neither is up to the job of replacing FlightTrack.