Multicolr Search Lab : We extracted the colors from 20 million Creative Commons images on Flickr to make the images searchable by color.
Diffee Checker : Instant visual diffing with CSS blend modes!
Simply enter the sites you want to compare. Locally hosted addresses and files also work (so you can see ...
LGTM.in : Looks good to me (LGTM) is the most popular comment on Github, perhaps. But LGTM is boring. So we spice it up with some images.
Litmus : Test and track your emails. Email previews, analytics and spam filter testing.
Micoo is a pixel based screenshots comparison solution for visual regression test