Every stand alone GPS and every software i am aware of has a dedicated hardware or software button "nearest airfield". While in the situation of needing the nearest airfield, i'm not quite sure if I remember the way to this function - not to speak of the inconvenience fo a distressed pilot to tap the correct buttons. At least the ipad mini and ipad offer enough screen estate to put a little button in.

So my suggestion: integrate a small "nrst"-button on the screen in flight mode (either auto detect ipad mini or make its existence configurable) which produces a menue ordered by distance. In the menue give airfield name, distance, bearing

AND

tower frequency.

That would be a perfect addition for me.