What are some alternatives?
Imagify - Optimize and resize images online and through your CMS.
Transmit - Transmit is an FTP client for Mac OS X and Mac OS Classic (which is unsupported).
way2enjoy - Try image Optimizer. Compress and optimize image,PDF,MP3 by w2e image compressor. Resize image, compress image by lossy/lossless image optimization.
CodeKit - CodeKit allows you to optimize the performance of your website by automatically and efficiently compiling a variety of popular languages.
TinyPNG - Make your website faster and save bandwidth. TinyPNG optimizes your PNG images by 50-80% while preserving full transparency!
JPEGmini - JPEGmini - The Photo Optimization Tool Trusted by Tens of Thousands Image Perfectionists