Although this isn't an actual download, I think it's so cool that I want to share it with everyone!  Here is an excerpt from the size that explains what this handy online tool can do:

Simply pick one of the disk colors above (Heatmap is selected by default), drag a D64 image from your computer to the webpage, and drop it. After a second or two, a visualization of your D64 will appear on the screen.

You can also find this and many other handy links at a new website I'm working on - https://commodore.bookmark.computer