The most basic of shaders. Features 1 controllable color
A single texture that can be tinted
The full code shows Alpha Test, Alpha Blend, and Additive Blending
How to make a shader double sided in Unity
Adding a light to a shader
Extending lighting to multiple lights
An approach I found to approximating multiple lights in a single pass for Unity.
Faking lighting with a frensel, based on the main directional light.
Adding a specular highlight
Specular mapping via a texture alpha
Pixel lights and normal maps.
An emissive shader with a way to fake glow in texture space.