Ranked in these QuestionsQuestion Ranking
Pro Simple UI
Kaleidoscope has a beautiful and simple UI. It displays the two files that are being compared side to side, highlighting all the differences in a way that's easy to understand.
Pro Diff within a line
When working in code, line-by-line diff can still be hard to spot small changes within the line. Kaleidoscope will highlight what has changed.
Pro Supports comparing folders
Pro Image difference viewer
Kaleidoscope supports image diff viewer in addition to git diff. It's able to find even the slightest changes between two versions of the same image.
Con Mac OS only
Kaleidoscope is a Mac OS X only app.
Con Paid software
Kaleidoscope is not free, costing $69.99.