AssetsProcessor 1.1 for Mac was available to download 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 Harley.xk. The software is included in Developer Tools. We recommend checking the downloaded files with any free antivirus.
From the developer:
Assets Processor is a simple tool to process your Xcode image assets. The application allows you to scale 3x images to 2x and 3x or 2x images to 1x if required. In addition, the program allows you to upscale 2x images to 3x. Furthermore, you can rename file names with the name specified in the image set.
You may want to check out more software for Mac, such as Browsealoud, solr or joomla-, which might be similar to AssetsProcessor.