With Apple's new iOS 11 exposing the file system to users and allowing drag-and-drop and other cool things, it seems to me that it's just a matter of time before FileMaker Pro is ported to iOS. On Win/Mac, seasoned developers clamor for a pure text-based scripting environment, but FMP's "dialog-driven" scripting interface might actually be a help, not a hindrance, on iOS.
Bento (if I recall) allowed the creation of layouts in their iOS version, so the folks at FMI obviously thought that the concept of developing iOS apps using iOS tools was viable.
I bet 2018 will be the year for iOS FMP. Any takers?