For me the killer feature of Zim is the native integration with Git. It's super easy to write and commit, write some more, commit again. You don't even have to leave the editor interface. I've coupled this with git pre-commit and post-commit hooks which basically ensure that the changes are always pushed to GitHub. I've found a similar application for Android called GitJournal. Unfortunately it doesn't do the wiki sy…
On Android I use Markor to edit text -- it also recognizes Zim Wiki format if I remember correctly. And then Termux is nearly a full Linux distro with convenient touch icons for things like Tab, modifier, and arrow keys -- I installed the git package for it and used that to push/pull to my GitHub repo. Maybe that could be a solution for you?
I've used Markor but there's too much file management involved, instead of organising pages at a higher level and letting the app handle the filesystem ops.