I'm the Facebooker maintaining this tool. We use it internally and externally and it represents a "platform application". It runs on a separate domain (www.fbrell.com) and is iframed on the linked page on facebook.com.
On a more general note, is anyone else tired of seeing "X uses Y" posts? It feels more and more that, in the Valley, namedropping is a way to ensure your own relevance, whether you're a business or a landing page or a person, and I'm getting tired of these appeals to popularity.
Funny that not even Facebook devs bothered to change the colours to use the FB brand blue. Twitter Bootstrap slowly becomes synonym to "basic unstyled webpage".
It's all open source actually: https://github.com/daaku/rell.
Even better, it's written in Go :)