Edit Depth of Field for Mac

From HumanSoftware:

Edit Depth of Field helps you to keep the attention of viewer by blurring the background, moving all of attention toward the main component of the photo. This technique is achieved when the photo is taken, but now with DepthField it can be achieved easily on any digital image. This tool provides the great advantage of not having to use expensive hardware and is giving the photographer the ability to have more control over the final result.