Does Spanbox have a mobile app, or is it desktop only for now?

Desktop only for now, there's no mobile app yet, it's on the roadmap but not out. That's a deliberate fit: Spanbox is built for the 'I have fifteen apps open on my computer' problem, which is a desktop pain more than a phone one (your phone already stacks apps neatly). On mobile you'd still use each app's own native app. So today it's Mac, Windows and Linux, and you run it on the computer where the app clutter actually lives.

No mobile version currently. Makes sense to me, the multi-window mess it solves is a laptop/desktop thing. On the phone the individual apps are fine on their own.