Preact.js - Preact is a fast 3kB alternative to React with the same modern API. Components & Virtual DOM.
Flickr - image and video hosting website
Inferno - An extremely fast React-like javascript library for building modern user interfaces.
Imgur - Imgur is a free and simple image hosting service with image editing feature. Signup is optional.
Glimmer - Fast and light-weight UI components for the web
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.