Originally Posted by Midland63
Something to with the fact EFB apps don't show your position on the ground movement charts so you buy your own GPS to add that functionality???
Either: the GPS in the ipad is not strong enough to get a signal through the 787 windows, but a dedicated GPS receiver like a Bad Elf is (that is the case with me), or the ipad doesn't have GPS (eg it's a wifi ipad).
I don't think these aeroplanes have topo maps (mine certainly doesn't) so I use(d) the external GPS for positioning for my tablet so I can see where I am on Memory Map/Maps.me etc. Good for when the pax ask "what's that lake over there?".