Digging around the web the other day looking for GLSL ES info and I came across this site, it’s a nifty online editor, compiler and previewer.
It comes with some examples of 2D, 3D and Plane Deformer shaders and it can take input from Time, Mouse(LMB with current pixel and clicked pixel), Viewport Resolution and 4 Texture(sampler2D) channels.
Happy Shading!