If it's important -- either for typical use or as a differentiating feature -- to use this on a phone I would go with a mobile-first UI that can scale up to des

If it's important -- either for typical use or as a differentiating feature -- to use this on a phone I would go with a mobile-first UI that can scale up to desktop rather than a desktop UI that somehow needs to compress itself down to fit in a mobile UI. I would check out the work Ionic has done with the mobile-first/PWA approach.