Thats cool , every day is a school day, yead black point only works with relative anyway :)GIMP uses black point compensation when "relative colorimetric" is chosen as the Display (default) rendering intent, and does not use black point compensation when "perceptual" is chosen as the Display rendering intent. (GIMP 2.9 provides a check box for black point compensation.)
The Op was looking for applications that preferably ran on OS X. There is one app that I forgot about, it is not free, but neither is it as as expensive as many of the main and better known competition.
http://www.pixelmator.com/mac/
https://itunes.apple.com/us/app/pixe...ign-mpt=uo%3D4
Another one here using gimp. I find it really easy to use dor the basics in A4. Wont print A3 tho