Chris check out https://sickpay.lv.com/ I have customised the feedback button there. Just add a class above it in the css styling:
.lv .sprintrFeedbackNode {
background: transparent url(images/layout/feedbackButton.gif) no-repeat !important;
color: white !important;
cursor: pointer !important;
height: 102px !important;
position: fixed !important;
right: 0 !important;
vertical-align: !important;
width: 100px !important;
z-index: 10000 !important;
bottom: 0 !important;
top: auto;
}
.lv is on the body of the html.
There's a sliding panel widget and feedback API in the appstore, you should be able to customize the sliding panel and use the feedback api to post the data back to sprintr.