Non-Linear Wiki/Note App Suggestions

Hi! Yesterday I found a note-taking service which I fall in love (https://notabase.io). Problem is, it's in alpha stage and doesn't have backup or export option, so it's not reliable to use right now. Also, using it on mobile is buggy.

What I'm asking is if you people know there is any more mature similar app?

Tried TiddlyWiki which feels like notabase, but it's not as fast as notabase to create new notes/links and to navigate notes, also it doesn't use Markdown. Also couldn't figure it out to use it with Netlify/Github.

Thanks!