Ghostwriter isn't a WYSIWYG. You edit the markdown as plain text and Ghostwriter does a live preview of the markdown formatting.

It just depends on how you like to work. Some people like to work with the raw text/markdown, and others prefer to not mess around with markdown.

The only one I can think of off the top of my head would be Zimwiki.

I don't know about any Android compatibility for Zim. It has been a long time since I have used it.