The 2.3 version of ImageReducer for Mac was available to download on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. This Mac application is an intellectual property of Runecats. The application belongs to Developer Tools. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe.
From the developer:
Do you develop iOS or OSX applications? with ImageReducer you can easily resize your @2x and -hd images in seconds!
This make it easy to create all of the non-retina graphics so you can resize them in a matter of seconds
ImageReducer supports .jpg .png .tif and .bmp formats.
All you have to do is drag the @2x or -hd named image to the ImageReducer app and chose the folder you would like the reduce image to output. That's it!
You may want to check out more software for Mac, such as eclipse-php, Prototypes or Affrus, which might be similar to ImageReducer.