Thanks for the reply mouser
IMO this is not an 'effect', but rather a improvment of the capture engine. Technically speaking taking a full screenshot is get hWnd 0x00 DC and convert it to bitmap. But apps like
Layers is a innovation in the capture process, you have to iterate the active & non-active window to get the whole picture.
There are a lot of screen capture software out there, but one function might make Screenshot Captor unique is layered screenshot. If Screenshot Captor do not implement this, I think some other software might fill the gap.