The idea of this add on is fantastic. Lots of potential and I'm glad you guys are looking into this. After loading the plugin on 2 different wordpress installations I found this notification bug.
1, On one site that the signature plugin worked on, when the email notification was sent with the hyperlink to the signature image, the URL of this image would end with 'New', as seen below:
This is an erroneous hyperlink, but when I remove 'New' from the end of the URL, the path is correct and the image appears on the screen.
I am running this site on SSL, using the latest version of both wordpress and Gravity Forms. GD Library is loaded and the latest of PHP is running.