Versions.app: How to select Kaleidoscope.app as diff tool?
From the Kaleidoscope app go to Kaleidoscope menu > Integration...



Install the ksdiff tool


Quit and relaunch Versions and Kaleidoscope should be selectable.


If that doesn't work, check with Black Pixel's amazing support team after being sure you have build 104 of Kaleidoscope 2.0