Resizing.app - Image resizing has never been so simple with free online resizing.app. Convert, optimize, resize images with ease and for absolutely free.
Responsive Viewer - View multiple screen dimensions in one view
Image Resizer for Windows - Lets you resize images by right-clicking.
Responsinator - Designed to test responsive websites on different devices.
Icecream Image Resizer - Image resizer by Icecream Apps is a program to resize images fast and free. Windows version. Free Download.
Responsive Website Test - Test any website on desktop, mobile, and tablet