Firstly, awesome IPhone Skydemon app! It's very good indeed. I have some suggestions though:

Design the PLOG to a readable size (tailored to the IPhone?), similar to the Radio frequencies?

Introduce both the PLOG and Radio functions (two frequently used functions) to be accessed in a similar way as that of the "N W P F" boxes are presented in the "Fly" page. I'm suggesting two more little additional boxes that would quickly take you to PLOG and Radio respectively.