I needed a plugin that I could automatically save images based on regex or dimensions and couldn’t find any available so I decided to get one coded instead. It is in beta form right now as there are a couple features and bugs needing to be resolved still but the basic functions work. I use it to save ads so that I could see patterns or get design inspiration from others.
Download link: image auto download firefox plugin version 0.1.
Please provide feedback on it in the comments section below.