Never understood that kind of "improvement".
Most of the changes look like a simple color palette change with a bit of darkening, and maybe some additional HDR over it.
All it does is just damaging the true color.

Feels more like an FX plugin for those who don't want to post-process their screenshots in Photoshop.
Don't get me wrong, It is a good tool, and if you like color skewing - it is all up to you, but I wouldn't call it "improving".