Object Placement Tool - it's a powerful editor extention that allows you to populate your scenes in minutes using simple mouse click instead of regular drag & drop of prefabs and setting all rotation and scale variations by hand. The core feature of this tool is "Physics Placement Mode". In this mode you can place your objects with the help of physics. You can easilly create huge amount of objects dropped onto each other, for example - the big heap of books like that shown in this video-demo