pixelmator

Sitting quietly in the Tools panel of the popular image editors Adobe Photoshop, Photoshop Elements, and Pixelmator, is the Gradient tool, a wonderfully useful painting tool that lets you create a soft, gradual transition from one color to another (or several). But besides using the tool to add color to your designs, you can use it inside a layer mask (referred to as a gradient mask). By setting the two colors of the gradient to black and white—to conceal and reveal, respectively—the tool lets you fade layer content in interesting ways.

Browsing the App Store for new photo-editing software can be overwhelming. There are dozens of image editors, and it’s difficult to tell which is the right one for your needs. If you’re already using iPhoto or Aperture, stick with those free programs until Photos is released in 2015—it may be all you need.