CMS Detect was created as an extention of Scan WP. While Scan WP was created in order to detect Wordpress themes and plugins, there is also a huge market out there of other sites besides Wordpress. There are tuns of CMS' and frameworks out there that people use, that could be detected in order for you to build a similar site.
If you are an unexperienced web developer or just a business owner that wants to create a website similar to another, CMS Detect is exactly what you need. Just detect how it was built, head over to the site and start building. It's as simple as that.