I use https://www.lifepim.com https://www.lifepim.com (disclaimer: I wrote it) for all my notes now. It has a simple cut down version of markdown with headings

I use https://www.lifepim.com https://www.lifepim.com (disclaimer: I wrote it) for all my notes now. It has a simple cut down version of markdown with headings, code blocks and linking which works very well for me. I manage the structure through the folders feature so notes are grouping into my categories (Dev, Design, Study, Fun, Home, Work, Health, Business)