I just finished reading "How to take smart notes" by Sönke Ahrens. It's mostly about Zettelkasten. Been looking for a good tool to implement it. Didn't like any of them very much. Zettlr at least seems tolerable, and it uses plain old Markdown files so it's easy to store the notes in git.

Something with phone support would be nice, hell even just read-only mode would be great. Best of luck, and please report back if you can set up a landing page or a github repo or something else we can poll :-)