I created this account just so I could thank you.
(A post from Sarkut lead me here. (My thanks to you as well))
This is exactly what I was looking for.
I wanted to remove an entire colour (Like Chroma Key).
All the other places I looked at, went on about using multiply (Doesn't actually remove the colour....) or the magic wand tool. Except I wanted to remove the entire colour. While Magic Wand works, It is inaccurate and time consuming if the picture is complex. I was sick of using it.
Grim Reaper is far more accurate and instant. It should be standard.
So I thank you for making this plugin compatible and availible for people to download.