Smallpdf - PDF document management and conversion suite
Big Photo - Overcome the image resolution limit on iOS devices
iLovePDF - Free online PDF tool set
TinyPNG - Make your website faster and save bandwidth. TinyPNG optimizes your PNG images by 50-80% while preserving full transparency!
Kingshiper Image Compressor - With Kingshiper Image Compressor, you can easily compress, optimize and reduce jpg, jpeg, png, svg and gif file to a smaller size in seconds.
Bandwidth Hero - Browser extension which saves data by compressing images