I asked moderators to edit your post and add hyperlinks to the services. It would be very convenient if next time you could do that yourself so people can actually follow easily the things you mention.

Now to your question. All this sites have the code explanation:

• http://mypiday.com/about-this-site
• https://www.imageidentify.com/about/how-it-works
• http://wolframlang.tumblr.com/post/126839004257/become-a-web-app-ninja-a-walk-through-of-the-code

If you mean the actual final nice outlook of the site I think it was a custom HTML design and not Wolfram templates. You can deploy HTML to the web:

CloudDeploy[ExportForm[Import["http://example.com/", "Source"], "HTML"]]