I was the original developer if this, and I don't believe anyone's made it into an addon. It currently stands as just a standalone PHP script which pulls information via HTTP. I wouldn't be opposed to anyone converting it to an addon, though.
When i have time i will me porting my own Signature Maker system over to this system.
You can try it out on my site here www.totally-scripts.com you will need to signup to be able to view it and try it.