The heraldry presented on his site is really poorly done. Lack of adequate contrast, color on color, metal on metal...
the actual tool is at worldspinner.com/heraldry/device_editor/ It's not bad, but is missing the stains (which are historical, albeit post 1500ish...) of skye/bleu celeste, sangue (blood red), murrey (dark purple), and tenne (orangish tan).
It's rather simple, doesn't cover subordinate charges, and a number of other elements.
(I am an SCA herald. Don't use that tool for ginning up SCA submissions...)