We have recently started an Itch.io page for our smaller assets which will be listed for free or very cheap. Currently we have released the Volumetric Light Function for free, This is a solution for Light Functions on Volumetric Point/Spot Lights, as the current light function system is not supported for them. This asset is great for specific use cases like underwater caustics, god rays and projector lights.
Fluid Interaction Tool is a new asset currently being processed with the UE4 marketplace, This tool is a per-bone fluid propagation system for your skeletal/static/physics meshes and It can be easily applied to any material surface.
We are happy how this asset has turned out and think it will be a great addition to the ShaderSource library.