https://blendermarket.com/products/blendit

Full dynamic one-click solution for material blending of objects.

Main features:

• Easily create material blend of selected objects with active
• Non-destructive operations: create, apply, remove material blends
• Option of executing the operations for all blends of source object
• Real-time dynamic blends works in viewport, Eevee and Cycles
• Option automatic create material from blended objects
• Option to Blend Normals of objects
• Easily tweak individual blend of object
• Easy tweaking of all blends of source object
• Blend styles: Height maps blending, Noise and Custom texture masking
• Preserve texture scale from source object with mapping options