Difficulty is of course subjective; I have 10+ years of functional programming experience but was completely new to Swift; the core functionality took less than a week of 4ish hours a day. Apple's EventKit API is very developer friendly and Markdown is a well known format so that made things easier. I'm not a frontend / UI tradie so spent another few days learning SwiftUI & making things look quality (and TBH I think that quality is not where I want it to be). So to answer your question... not really?