Download of iResizer 3 3.1 for Mac was on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The actual developer of this software for Mac is Maxim Gapchenko. We recommend checking the downloaded files with any free antivirus. IResizer 3 for Mac lies within Design & Photo Tools, more precisely Viewers & Editors.
From the developer:
iResizer scale an image without changing important visual content such as people, buildings, animals, etc. It also can be used to remove portion ot the image in a consistent way. For example, you can turn a landscape picture into a square picture and close up the space between people in a image if they are a long way apart.
You may want to check out more Mac applications, such as iResizer or iResize, which might be related to iResizer 3.