MDNotes 4+

Great integration with Files, clean menus, multi-tasking support is perfect.
Be aware that if you use dark mode, you will struggle to read LaTeX equations because they default to \color{black}. The developer seems to be working on the math features actively, so perhaps future developments will allow for setting the \color{white} or ideally \color{-\pagecolor} to the whole document/app.

I’ve been exploring iOS/iPadOS text editors to supplement building a Zettelkasten archive that lives in a Resilio Sync folder mostly managed on a laptop with either TheArchive or Obsidian (neither of which as mobile apps yet). MDNotes turns out to be the winner for iOS/iPadOS mainly because it works correctly with the iOS Files functionality for external services - particularly creating new files, renaming files and displaying the full file name. So many other fine text/code editors manage to screw up this basic functionality for external services that aren’t Dropbox.

I use a markdown editor as my self-hosted notes and to-do list manager because I can create bidirectional links which are very helpful for writing and studying. I needed a mobile solution for quick notes, storing quotes, etc.
This app works with Files which means it works with my home server. It would be great if a few other features existed, but it does what it needs to: markdown editing.