Maybe a clarification of my comment would help here: I meant that an iOS app would have the functions of the web app but also provide swipe, share extension, import/export from other iOS apps and connections to iOS services like calendar, contacts and images.
While not a game changer features themselves, it would make the iOS customer segment happier but require an iOS programmer on staff. These things can be added in the future without losing paying customers now (like WorkFlowy lost me).