This is sheer brilliance, and it’s really well-executed. Too bad Apple hasn’t seen fit to include this core functionality in iOS. This is truly a game-changer in that now, as a designer, if I want to round-trip files from OS X to iOS — Pages/Numbers/Keynote, especially —I needn’t sacrifice typography. Other apps, like OmniOutliner & OmniGraffle work, too. Not every app sources fonts in the same way, though, so be aware that apps like Byword, iThoughts, Notesy, or Day One don’t work with AnyFont, and system apps mostly don’t allow you to choose fonts at all. Go in knowing that, and it’s the best $2 I’ve spent on iOS. :)