Thank you so much! I'm reworking app flows this week and I was hesitating about removing this demo. I'm taking this comment as a sign that it's got to stay.
One bit of feedback - on mobile there’s doesn’t seem to be an easy way to go to your homepage from the linked post. Clicking on the “FF” logo brings up a menu but none of those take you to the root page. And of course manually editing the URL is awkward on mobile.
I suggest don't remove the demo. I have a watermarking app https://watermark.ink the only reason there are non-english speaking users is because of the landing page itself is the app.