I watched the demo but, unless I'm missing something, I can't see any advantage over just dragging out another Chrome/Firefox/Edge window and putting them next to each other on the same screen. The UI is kind of strange, too.
It seems like an uphill battle to create what is, essentially, just a fixed-window browser.
I guess one of the advantages of Nanosai Boards over web browsers becomes very clear once you start having loads and loads of tabs open in your browser!
It seems like an uphill battle to create what is, essentially, just a fixed-window browser.