Support for PNGShrink
Pngquant is a library for compressing PNG images. It is used by many tools and websites to compress and optimize PNG files. PNGShrink for OS X uses this same library so you can optimize batches of PNG files in an easy and fast way without having to upload them to somewhere.
No. The optimization is done on your own Mac. This means optimization is not only much faster, it also guarantees privacy, security and non-disclosure of your (or your customers) content.
No. You select a target folder and the optimized files will be stored there. Your original images will remain the same.
PNGShrink for OS X can batch process PNG images, decreasing their file sizes, keeping transparency and quality. More information.