imgix - Real-time Image Processing. Resize, crop, and process images on the fly, simply by changing their URLs.
TinyJPG - Compress JPEG images with perfect quality and file size
Cloudimage - Cloudimage.io is the easiest way to resize, store, and deliver your images to your customers through a rocket fast CDN.
Promo Instant Image Resizer - Automatically optimize images for web & social media (free!)
Sirv - Dynamic image processing, hosting and rich-media for retailers and eCommerce.
Compressor - Compressor adds power and flexibility to Final Cut Pro X export.