Patterninja - Create patterns online
Doodad.dev's Pattern Generator - A free tool for creating unique, royalty-free, repeatable patterns.
Pattern Monster - Pattern Monster is a pattern maker app to create vector patterns for your projects
Patternizer - Create awesome background patterns in just a few minutes
PatternPad - Create beautiful geometric patterns
SVGeez - SVGeez is a platform that offers many CSS SVG backgrounds and lets you customize and download them for free.