Download Distortion Shader Pack FREE Unity. 

– Works for PC 
– Works for consoles 
– Works for mobile 
– Works for VR (no singlepass)

This distortion shader package enables you to add scene distortion by drag and drop the prefab into your scene. Included are simple image distortion and advanced render texture distortion shader.

Can easily be used for heat or ice distortion. Even useable on particles because of optimized rendering.