Adobe Photoshop - Adobe Photoshop is a webtop application for editing images and photos online.
ImageOptim - Faster web pages and apps.
Polarr - MacOS, Windows, iOS, Android and online photo editing tools & free photo editors.
FILEminimizer Pictures - FILEminimizer Pictures compresses JPEG photos, TIFF, BMP and PNG images and pictures by up to 98%.
Fotor - Fotor is an all in one visual platform. It includes photo editor, collage maker, and graphic designer. You are free to make a visual look more beautiful.
Shrink O'Matic - Shrink O'Matic is an AIR application to easily (batch) resize (shrink) images.