Gochyu's WordPress.com Theme Detector is the first of its kind - and WELL OVER DUE. There are several WordPress theme detector's out there, but this is the first WordPress.COM as supposed to WordPress.org.
Not only are we the only WordPress.com theme (and plugin) detector, we are also the only detector that can even tell the difference! Any other detector will just assume that a WordPress site is a WordPress site. Not realizing that in reality, a whole bunch of the sites they are detecting aren't what they think they are.
We have the ability to detect any type of WordPress.com configuration that exists (there are a few), we can detect the plugins being used on each site too.
Depending on the type of WordPress.com functionality, a WordPress.com can use WordPress.org plugins. If we detect such a site, we will add a WordPress.org icon next to the plugin, letting you know that it's in fact a WordPress.org plugin.