Whimsical Wireframes - Lightning fast wireframing with real-time collaboration.
Patterninja - Create patterns online
WING - A phone carrier that is actually nice to you.
Doodad.dev's Pattern Generator - A free tool for creating unique, royalty-free, repeatable patterns.
Spectre.css - Lightweight, responsive and modern CSS framework for faster and extensible development.
SVG Stripe Generator - SVG Stripe Generator is an easy-to-use tool that enables you to create unlimited stripes and then download them to the device.