ShaderFrog is described as 'Shader Frog lets you create visual effects by composing two or more shaders together, and tweaking their parameters. You can build a complex effect out of simple components. You can then export your shader for use in your THREE.js game or application' and is an website in the development category. There are more than 25 alternatives to ShaderFrog, not only websites but also apps for a variety of platforms, including Windows, Linux, Self-Hosted and iPhone apps. The best ShaderFrog alternative is Bitspace, which is both free and Open Source. Other great sites and apps similar to ShaderFrog are Alma.sh, SHADERed, Shadertoy and Shader Editor.