ImageOptim - Faster web pages and apps.
GPUImage - GPUImage is an open source iOS framework for GPU-based image and video processing.
TruePNG - Command-line PNG optimizer.
Cloudimage - Cloudimage.io is the easiest way to resize, store, and deliver your images to your customers through a rocket fast CDN.
TinyPNG - Make your website faster and save bandwidth. TinyPNG optimizes your PNG images by 50-80% while preserving full transparency!
IMG.LY - Power Your Apps with IMG.LY | The Leading Provider of Design, Photo, and Video Editing SDKs