Stack every second image

I very often shoot more images than needed, and I wondered if I could delete some of them to save space on my drives. It would be nice to have a function: stack every second image, and if the result is good, an option to delete the excessive images. Or maybe even make StackCheck tell me: every other or even every fourth image would have been enough.

Just imagine once your software has reached 100k customers how much harddrives that would save and even make an impact on the environment ;).