I am building my own org-mode app for iOS. It is not an easy task, but it is in progress and I am optimistic about it. I've also decided to open source my org-mode parser framework (written in pure swift 3). Code can be found here. I am not worried about being a competitor of a super successful app like editorial, because the idea is to bring mighty org-mode to iOS. So feel free to use it. Oh, contribution is always welcomed.