You can use FltplanGO on the iPad. And it is free, but differ greatly from iFly EFB. I used it for filing IFR before Garmin bought them out. I expect Garmin someday will make it a subscription service too!
Garmin seems to be only interested in Garmin and not their users. I have several Garmin products but cannot use my GTX345 with my preferred EFB, iFly EFB! To use it I have to go to FltplanGO or buy a Garmin app.