Best way to fax from iPhone

Hey. I ran into the same situation and went through a bunch of apps before finding something solid. I found Municorn Fax through an AppleInsider review and gave it a shot.
It’s a lightweight, well-built app that lets you fax from iphone with zero drama. You can scan pages with your phone’s camera, enter the fax number, and send. It worked the first time, didn’t crash, and didn’t require me to subscribe before testing it out. The UI is modern and doesn’t feel like it was ported over from a 2005 desktop version.