PixelFed - PixelFed is a federated image sharing platform, powered by the ActivityPub protocol.
Imgur - Imgur is a free and simple image hosting service with image editing feature. Signup is optional.
DragNDropz - DragNDropz offers free image and file hosting. Create image galleries, edit and organize photos, share files, move uploaded files into folders, and more.
imgbox - Imgbox is a free image hosting service.
IrfanView - IrfanView ... one of the most popular viewers worldwide.
ImgBB - Upload and share your images.