picinfinity - Picinfinity is an image retaining/proxy site.
Uppy - The next open source file uploader for web browsers
Libris - Libris is an asset management for photos and videos.
Filestack - Simple file uploader and robust APIs for uploading, transforming, and delivering any file into your app. Filestack is a collection of tools and powerful APIs that make it simple to upload, transform, and deliver content.
Imagesocket - A different kind of image hosting
Uploadcare - File uploading, media processing & content delivery for modern web apps