Our infinitely powerful editor.
update for later generations: https://org-roam.discourse.group/t/import-of-obsidian-notes/609/3
it seems to be easy and seamless to use org-roam with md-roam, and use obsidian on mobile and emacs on your real computer. I might update this post with more details once I tried it.
I am in a similar boat. I decided to write my own app (learning android development so it's going slow).
I was using orgzly earlier but it doesn't fit in with org roam workflows.
Also check out logseq and its mobile app. I have heard you can make it work since it can use org mode files as the backend.