Placemat - Pretty nice placeholder images.
Gradient Cards - A simple and beautiful list of editable gradients
placeholder.pics - Lightest way to include placeholder images in your design
Web Gradients - Curated collection of 180 free fresh background gradients 🚀
Placeholder Loader Creator - SVG component editor to create placeholder loaders
CSSGradient.io - As a free css gradient generator tool, this website lets you create a colorful gradient background for your website, blog, or social media profile.