I love OmniGraffle for OS X – its my go-to app for developing software wireframes in my business. When I got an iPad Pro and an Apple Pencil, using OmniGraffle was one of my top two reasons for doing so. However, I have learned to my astonishment that iOS OmniGraffle randomly reverts to earlier saved versions, causing me to lose substantial amounts of work. Ill be working on a wireframe, then I close the document. I make sure OmniPresence syncs it. I re-open the document later and much of my previous work has disappeared. This app presents an unacceptable risk for professional use and should be avoided at all costs. My comments apply only to the badly flawed iOS version, not the excellent OS X version.