As we were creating our app with Scenekit, I had the chance to create a few fun shader modifiers for our app. Shaders were written in Metal, but the basis for how they work is translatable to all other shader languages and node-based shader systems.
A "hat hair" shader
A shader for the t-shirt to allow flexible combination of primary + secondary colors and a decal
A "fade to black" effect that can be keyed with positional values
Pool water shader
Not a shader, but a demonstration of clean optimization I did on existing dense assets