Sorry, I don't know of one for iPhone, iPhones are fairly locked down anyway. But a cheap £10 Nokia brick has call recording without announcements, if that's at all useful.
I just use LibreOffice Writer for odt, Folio (Linux) and Print Notes (Android) for markdown, and Syncthing to sync between my devices. If I need to share it with others, I either copy a specific file or just share the zipped root folder.
I mean the Voldemort of HPMOR, Harry Potter and The Methods of Rationality, a fanfiction by Eliezer Yudkowsky