You can define a flight area on Maps Made Easy by creating a boundary. This will let you define the survey area, not the actual flight plan itself since that is done on the iOS device.
You could also define a polygon or linestring in Google Earth and import it into Map Pilot as you normally would (via Email or AirDrop) but rename the file from sample.kml to sample_boundary.kml to import as boundaries and linear plans. Adding the _boundary to the filename tells the system to import is as boundary definitions instead of just guidelines. The imported data will show up in the File Manager screen.