At the time, The Next Web spoke with former Apple employee Michael Jurewitz and the rest of the Black Pixel team about Kaleidoscope 2:
Kaleidoscope 2 is a lovely comparison app that allows you to take two or more files, folders or images and compare them to one another. The applications are broad, with benefits that swing from developers on one end to those simply looking to compare two images side-by-side. It has full integration with Git, Subversion, Mercurial, and Bazaar. The app can be used as the default conflict resolver for code with its command line integration or simply to check the changed passages in a collaborative word document. It's beautifully designed, fast and wonderful to use. It's become an essential part of my toolkit already.
Kaleidoscope 2 is currently available on the Mac App Store [Direct Link], directly from Black Pixel or as a 15-day trial. It's available for $35 through January 30th, after which it will be $70.
Article Link: Black Pixel's Comparison App 'Kaleidoscope 2' Goes Live on Mac App Store