Piio - Generates responsive images so you don't have to optimize
Squash 2 for Mac - The easiest way to compress and optimize images for the web
Imagify - Optimize and resize images online and through your CMS.
Image Resizer for Windows - Lets you resize images by right-clicking.
Crunch - Crunch is a No Judgment Gym that believes in making serious exercise fun by fusing fitness and entertainment. Join Crunch for all your fitness needs!
Resizing.app - Image resizing has never been so simple with free online resizing.app. Convert, optimize, resize images with ease and for absolutely free.