Try silver bullet https://silverbullet.md/

I migrated from Joplin to Obsidian a year or two ago. It was straightforward. With Joplin, I had to use the export functionality from the desktop app. That cleaned up any non-standard bits and allowed for a straightforward import into Obsidian.

Obsidian-Syncthing user here. I agree with what someone else said about no feedback from syncthing that it is or is not done updating files. Beyond that though, it’s a great tool that handles all my notes well.

Logseq to Obsidian.

Logseq's markdown is weird and not standard. Everything is indented and in a list, even headings. I love me some open source, but this is a hard no.

Open your logseq files in a plain text editor and compare with the standard. I spend much of my time editing them back to Markdown.

Syncing logseq is easy on Syncthing. The only issue being that one has to watch out for conflicts by not editing one on one instance before the other sends it/it is received, but that's a sync issue not Logseq.

Bro. Just try it with duplicate files.
You will find out if the pictures don't load.

As for syncing: I heard some use syncthing for that.
My personal problem with it is, that I can never be sure it's done with multi device usage as there is no feedback to tell me so.

I am using Obsidian.md both with a remote repository (built-in 1st party paid model) and a community plugin for another repository using remotely-save (which saves it to my personal onedrive folder).
Both options have an indicator that they are done saving.
But with remotely-save I encountered corruption when I turned on my pc which hadnt had connected in a longer time. And remotely-save is configured to stop syncing if >50% of files have been changed.
So now I am running a background task to zip the whole folder and purge the oldest one every week.

I haven't migrated apps (except ditching Evernote), but I use Obsidian with obsidian-livesync and it works great - typing on my phone live updates the notes on my PC. Downside is you need the self hosted software running somewhere

joplin -> silverbullet

happy with switch, fits my mind flow better. no folders or files.

Currently testing zettelnotes, as it has git support, and file encryption. (I know Obsidian has several encryption plugins and git support) Obsidians is quite slow on my phone (too many plugins 😅) and I wouldn't mind my notes being encrypted just for peace of mind.

Importing notes went quite good so far. I like Obsidians UI better as it is more polished.

First I was impressed by the extensibility of Obsidian, but over time I figured, I don't need most plugins on a daily basis.

I would like to have a markdown Editor on Android, that supports editing .md file stored in different folders, without the need of setting up a Vault or other setup steps.

I migrated from Logseq to Anytype. I just took the raw contents from the directories and imported them as markdown in the desktop client.

Since I moved to PARA, everything has been archived. When I need a page from the archive I edit it to make it look better.

Have you tried to open a joplin .MD file in a plain text editor? That is not markdown. Its markdown wrapped into some Joplin format.

Can it really be migrated 1:1 to another app?

I moved from Evernote to Joplin a number of years ago, and now self-host the Joplin server and use Joplin on all of my devices. Great app. I'm afraid I can't help with the migration from that to something else, though!

I just edit markdown files with neovim and sync with Syncthing. I don't have it set up on android, but you sould probably use markor to edit.

I was recently turned on to Notesnook and it’s been incredible. It really is a FOSS replacement for Evernote.

Getting sync server running is a bit of a challenge, though, since there is very little documentation for it. If you’ve ever set up an internet-connected server before, though, it’s not too hard to figure out. There’s a docker-compose.yml file that does a lot of the work for you.