This is my #1 app because it lets me do to my iPhone photos what I would normally do in Lightroom with my DSLR photos. High-contrast black and white. I love it.
This app could use an update for iOS7, because it will glitch out from time-to-time and not export photos. Also, sometimes the photos export upside-down. Which is easily fixed, but an extra step nonetheless.
andysapp about Noir Photo