Imgur - Imgur is a free and simple image hosting service with image editing feature. Signup is optional.
Sketch - Professional digital design for Mac.
Flickr - image and video hosting website
Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
Photobucket - Photobucket offers image hosting and free photo and video sharing.
Adobe Photoshop - Adobe Photoshop is a webtop application for editing images and photos online.