Does not Flight Mode ensure the phone while 'on' for games and videos etc already in it's memory does not have RF emissions to potentially screw up Aircraft electronics?
Am still not sure that when using the Aircraft's wi fi to use your own device to act as the IFE screen is 'Safe'
In the old days the command Turn off Devices was quite clear, however now devices are 'on' how do other passengers and CC know that the device it not affecting aircraft performance?