Thank you for adding this useful little bit of information to the forum.
I've downloaded ShiftN (hopefully without all the advertising guff which wanted me to change my browser's homepage) and had a quick look at it.
It seems as though it could be of some value but quite how useful it might be I am not quite sure. I don't seem to be able to see a Preview as I move the sliders in the manual window which is a bit of a disadvantage - unless, of course, I'm doing something wrong. And I'm not quite sure what the right window shows with all its squiggly blue and green lines.
But, as you say, it's yet another addition to the group of little free photo editing programs I have collected over the years!