Yes. I have a Pi4 running NextcloudPi image on it. I sync docs, pics, even backup my Obsidian vault. It’s worked really well for Quillpad in my experience. On desktop I use Iotas (Linux) if I need to update from that instead of my phone.

Quillpad is the closest I’ve found. It’s simple markdown files. It can sync with Nextcloud as well. I use it for any short note or lists. Long form stuff including journal, I use Obsidian (not open source)

I have two of their basic VPS and they’ve worked well. My few interactions with customer service has been less than awesome though.

Cryptpad has a very capable Kanban in it. No mobile apps yet, but I understand that is on the road map.

I was looking for a journaling app that didn’t have vendor locking, or required some weird export dump that messed your formatting and folders up. That lead me to Markdown and Obsidian. I love it. And when I die, that shit will still be readable by any basic text editor.