http://psd.tutsplus.com/tutorials/tools-tips/how-to-apply-filters-and-effects-in-pixelmator/

Pixelmator is an easy-to-use, fast, and powerful image editing app for the Mac. In this tutorial, we will explain everything you need to know about working with and applying filters and effects to your images using the Effects Browser in Pixelmator. In the process, we will show you how to sharpen your images, how to apply a miniaturization (tilt shift) effect, and much more. Let’s get started!