Android app "Afterfocus" for selective DOF (depth of field).
A great little FREE app that gives you the ability to mark out regions in a picture that you want out of focus.
This means you can give your images to look and feel of images taken on a more expensive fast lens with a wide aperture.
It has the added bonus of giving you the ability to apply some of those instagram style preset filters for added mood or feeling.
A simple idea, brilliantly executed, definitely one to download if you enjoy taking pictures, and giving them something extra, so they stand it from the crowd.