What are some alternatives?
Lepton - Lepton image compression: saving 22% losslessly from images at 15MB/s
ImageOptim - Faster web pages and apps.
File Converter - Convert & compress everything in 2 clicks!
Transmit - Transmit is an FTP client for Mac OS X and Mac OS Classic (which is unsupported).
Django - The Web framework for perfectionists with deadlines
PNGGauntlet - -Combines PNGOUT, OptiPNG, and DeflOpt to create the smallest PNGs