I couldn’t leave a comment on the reallySimple repo for clouddemo.js (it appears to be locked), so I am writing a blog post. I was able to run the app on port 443 and successfully register a WordPress.com site and a WordPress.org site using version 0.5.0 of the WordPress RSS Cloud plugin. When I ran my separate test script on the WordPress.org site, it worked, but I figured out that the WordPress.org site is caching the RSS feed, which explains why feed updates were not seen by FeedLand.
The code for clouddemo.js looks good, I am pleased that it could run on port 443, since I already had an app running on port 80 on my server and did not want to change it.