Lenka (US$2.99) is a simple app to help you create dramatic black and white images. The app was developed by famed photographer Kevin Abosch and it's starkly simple. To begin with, you frame your photo, which is visible in black and white in real time on your iPhone. There are only a couple of options: regular or high contrast. You can change the format from rectangular to square, and then you can start firing away. The only available editing tools allow rotation and cropping.