Joplin was dog shit when I used it. Basically it tries to save the file after every single character you type so if your document becomes long enough it starts using a shit load of data and crashing your phone. There was also something weird where you couldn’t scroll to the bottom of your note In a reasonable amount of time, I forgot what the reason was but overall the thing seems like typical FOSS dog shit where they’re talking about all these fancy features like nextcloud integration. if you just want to type a note, you know the most basic thing, it can’t do that, but of course the devs are working on some super advanced feature which is irrelevant because the base product doesn’t work. yes this was on android

And not to forget LogSeq (https://logseq.com) which is often mentioned in a row with the above and somehow the new kid in town. Works with local markdown files but lives in your browser (so useful even in environment with low privileges). Allows linking and querying notes and blocks swiftly.

I am building something similar browser based https://bangle.io

Syncthing solves the markdown sync issue for me flawlessly on every platform. You can always use Dropbox or any other plain old file sync service too (OneDrive, NextCloud, etc.). At the end of the day it's just a bunch of files so you can use anything--sftp, rsync, xmodem over dialup... it's just files.