GIMP - GIMP is a multiplatform photo manipulation tool.
Flickr - image and video hosting website
Adobe Photoshop - Adobe Photoshop is a webtop application for editing images and photos online.
Imgur - Imgur is a free and simple image hosting service with image editing feature. Signup is optional.
Krita - Krita is a professional FREE and open source painting program. It is made by artists that want to seaffordable art tools for everyone. Concept art. texture and matte painters, illustrations and comics.
Google Photos - All your photos are backed up safely, organized and labeled automatically, so you can find them fast, and share them how you like.