Material Nodes Addon - Blender 2.8

Update: Material Nodes V 1.2 is now available on GumRoad:

Soon available on Blender Market. The Material Nodes addon is an addon that contains a collection of useful nodes. You can find these nodes in the N-Panel of the Shader Editor. Currently the nodes available are suitable to add variation to the sterile, standard shaders in Blender but you can build a complete material with it.
The addon is in an early state and expect more nodes to come.

Alternatively you can also take a look at;

Material Nodes Addon,Blender,Addon,Blender 2.8,