ICNSmini 2.0 for Mac could be downloaded from 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 free Mac application is Ohanaware Co., Ltd. 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. The application lies within Design & Photo Tools, more precisely Converters.
From the developer:
ICNSmini IS a neat little application that reduces the sizes of PNG, ICNS, TIFF, Iconset, and Windows ICO images so you can make better Mac Apps and slicker websites. Actual compression rates will vary, as it depends upon the original content of the image.
You may want to check out more software for Mac, such as MPG Converter, PDF2JPG or Mac PDF to Flash Converter, which might be similar to ICNSmini.