Just use the Nextcloud notes app? It does markdown, technically it only edits md files in the notes folder. But markdown means lists
Edit :but alarms seems to be a no, you could use task.org if you got a Nextcloud anyway, checkboxes seem to not work as ‘[ ]’ but should
Edit 2: apparently I was too stupid to type properly, it does have checkboxes
Desktop: https://imgur.com/a/uBRibEG Mobile: https://imgur.com/a/fuljOtB
Not so sure about best but it does work kinda like you want to
I watched a video about the topic some time ago, it sheds some light upon the stuff
https://www.youtube.com/watch?v=rVwBuMX2mD8