Sliding the wool over your eyes
What this app appears to do is slightly blur the imported “Before” image. Moving the slider to the “After” position restores the original clarity! I compared the “Before” and “ After” sections of several imported images: the “After” is always identical to the unimported image quality, while the “Before” side of the slide is blurred compared to the original. If this App was not free, one could call it a scam.