Simple Heat Map Generator with JavaScript and Canvas – Simpleheat
Simpleheat is a simple and fast heat map visualization library which allows you to draw Html5 canvas based heat maps with ease.
JavaScript & CSS heat map
Create A Scroll Position Heat Map using JS and Canvas – ViewHeatmap.js
ViewHeatmap.js is a JavaScript library that generates a CANVAS based heat map on your webpage screenshot to visualize how far the visitors scroll down your page.