Q: OMG it doesn't work :(((((((((
A: You need to save the site (⋮ > More tools > Save site as). You might need to right click and open in "View".
Q: What won't work?
A: YouTube won't work. This site won't work if your admin is smart enough to block iframes. This site also won't work if the target site doesn't use HTTPS (look for "https://" in the URL. If it's "http://" instead, it won't work.
Q: My site isn't working! Help!
A: Refer to the question above. Make sure to include the FULL URL. E.g. "example.com" won't work but "https://example.com" will. Some sites don't let you embed them. You're out of luck there.
Q: I really like/hate the site. Where can I leave feedback?
A: Nowhere ATM.