It works

The frame rate is slowed down to allow better light visibility, but the image can be blurry if you move the phone too much. Turn on max power and set the phone down... Much more will be visible than with the standard camera app.
It does not allow you to see any better in darkness than with your own eyes. But, if you have a IR flashlight, it should work in total darkness... Unless there is a IR filter in the iPhone camera lens.

What I wanted from this app, is the ability to take video/pics in low light, as clearly as my own eyes see things. Use screenshot w/ the home+lock buttons... No video, unfortunately.

PathfinderLFD about Virtual Night Vision