iScale @3x is a tool for iOS and Mac application developers that automatically downscales Retina and Retina HD images to lower resolutions. All you have to do is drag and drop your @3x named images onto the window and let iScale @3x do the scaling for you.
-Automatically generates an @2x and a standard definition image from an @3x image. You don’t have to manually resize the images in an image editor anymore.
-Still supports generating standard definition images from @2x or -hd named images.
-Supports the @2x~ipad suffix! Drag in an image with the @2x~ipad suffix to generate ~ipad, @2x~iphone, and ~iphone suffix images.
-Supports the @2x~iphone suffix! Drag in an image with the @2x~iphone suffix to generate an ~iphone image.
-Supported image types include: .png, .bmp, .jpg, and .tiff.
You can purchase iScale @3x on the Mac App Store.