Ok, yes, it really DOES amplify the brightness in a dark room, and it filters it green as a special effect. When the sensitivity slider is moved toward the left (max sensitivity), there is a lot of signal noise, as would be expected when amplifying a dim camera image. If you don't like the green color, you can use the Photos app to post-filter it to monochrome to get a black and white image.
When you start the free version of the app, it gives you a Google ad, which you can easily dismiss - EXCEPT when it randomly gives you a VIDEO AD, which you have to watch 5 seconds! It is for this reason I'm giving the app only one star - offering video ads (which play at your selected volume level - in my case, LOUD) when the app launches will scare away any wildlife you were planning on seeing in a dark area.
Other than this BIG ANNOYANCE, it's an ok app.