I am working on Other Memory in two places. There is a Preview app for Mac and a free app for iPhone. The Mac is the workbench: this is where I place cards, connect them, read them together, and turn them into writing. The iPhone is for carrying the Zettelkasten, reading it, and catching something before it disappears.
I am also making sure that both apps work with ordinary Markdown files, and that the Mac can export the Zettelkasten into a physical form that continues on paper. That boundary matters to me. Other Memory should help me use the method without making the method dependent on Other Memory.