I’ve used it for all my websites (of which we export the code and lost locally), but just tested a new site through publishing it on Webflow ***.webflow.io
The result, blank. Nothing shows up. I then tested the Webflow website itself and I get the same error.
It won’t work on every device anyway only the device your canvas is set to. For example if you build your site to iPhone 6 size it’s going to look crap on a iPhone 5.