I had a lot of fun putting this together! It was just a personal project to see if I could do it. I envisioned a matrix of dots that, when hovered, would flip their color and slowly fade away. I works like a charm on the desktop. You can use keyboard shortcuts to change the color, and the CSS :hover attribute and CSS3 transitions make the effect work quite nicely.
My hope was to have it work just as well on mobile. In the end, I got it working most of the way, though there are surely some performance optimizations I can make with the speed of determining whether a drag action occurred through a dot or not. I would also love to have it support multiple concurrent touches. I didn’t use any kind of framework like Sencha, though that would be a logical next step.
You can see this in a separate browser window, or check out the Pen below. Fun stuff! Full disclosure: something’s off with this in Firefox, but it tests out in Chrome and Safari.