Kaleidoscope is a tool that allows you to spot the differences in text and image files and Review changes in seconds. Compare text in Blocks, Fluid and Unified layouts. Quickly navigate and search through the most readable diff you've ever seen. With four different layouts and exceptional performance, Kaleidoscope makes reviewing image files that much easier and quicker. Complete your workflow with Kaleidoscope. Git, SVN, Mercurial, drag and drop, it all works.
Be aware that Kaleidoscope v2.1.1 is crashing A LOT! I have contacted the developers twice in the past 6 months and they just shrug it off with nonsense replies that "...the developers are looking into it". Are they "looking" for over 6 months!? The problem is really simple. If you have two drives (say USB) and you want to compare the content of folders on one drive with the contents of another drive (using same folder structure), the first comparison passes, but after that, with each comparison the app will become increasingly unstable and eventually crashes. Who knows, it might even corrupt your drive(s) eventually. Does not worth 70 bucks for an abandoned app!!!
Summary
An abandoned app that crashes A LOT does not worth 70 bucks. I think the devs are just hoping for a few losers to spend 70 bucks on an app that is no longer maintained.