Mir Vadim has released Rayfire for Unity. His popular destruction kit plugin for 3DS Max.
The Unity version allows you to infinitely demolish 3d objects at runtime and preshatter items in Edit mode. Like the Max version there are several fragmentation types including regular voronoi, wood splinters, slabs, radial, slicing using planes and tetrahedral.
Using Clustering you can simulate and break them as more complex concave shapes. RayFire also provides Advanced Dynamic Simulation Control over simulated objects and demolished fragments such as activating them at a specified time. It also allows users to shoot, explode and affect fragments by wind and vortex forces.”
Find out more on the Unity Store.