Here's my SkyCatcher checklist PDF file if anyone wants to take a look.
dl.dropboxusercontent.com/u/89611087/...
It works very well in iBooks on IPad Mini 4. iBooks indexes one page at a time and saves your place as you switch back and forth between IFly and iBooks.
Works well on IPhone 6S Plus also.
I think something like this would work as a simple add-on for IFly GPS. You would simply add some sort of PDF file reader, put a "Checklist" button in place of "History" and give us the ability to upload our PDF checklist file which each person could create for their airplane. Better yet, have the "checklist" button take us to a directory with multiple checklist files for people who fly multiple airplanes.