Progressive Web App
A website that installs.
A PWA is a website that can be added to a home screen, opened without browser chrome, and used with no network. A manifest and a service worker, mostly.
Napkin is one. It installs, it works offline, and everything you type stays on your device in IndexedDB. Nothing touches a server. Which is exactly how I want it, and is also the thing that nags at me, because my own sheets end up stranded on whichever machine I typed them on.
Owl’s browser build reasons the same way for a different audience. Collaborators who don’t own the appliance still need to write when the network isn’t there, so a static shell that works offline is the entry point rather than a nicety bolted on afterward.