I don't think GradeQuick is available anymore. I've checked the official website, but it leads to the BlackBoard page, which I believe is something newly used. I've also used the built-in Search feature to locate the product, but there are help guides available and nothing else.
I believe they dumped the GradeQuick and replaced it with Blackboard software. However, you should contact them to obtain additional information: http://uki.blackboard.com/contact-us/index.aspx