You will be able to use Windows, iOS,and Android devices.. and any device with a browser (Edge/Chrome/Opera), so even a Mac or Linux.
All the platforms will share exaclty the same responsive look and feel.
But since, I don't want to store or handle any of your content (ex: configuration, with personal photos) the web version will allow to create everything as usual (or import like now), then it's up to you to export, and save in your storage the configuration so that you may reuse it later (via web, or importing it on a device within the App).
If you close the browser, or refresh the page, you will lose the configruation. (at least, for now.. I don't plan to handle your data in any way, I could, but I don't want to).