The ZeroAndOne.UnityEditor package adds a number of useful extension to the Unity GUI, and is available for download as a Unity package or a zip file. Import the package into your project, or unzip the zip file into your Assets folder.

Features:

• Examiner window, for deep inspection of your scene.
• Find menu to locate missing scripts and see which game objects are using a particular script.
• Various useful bits of code that you can use and refer to in your own projects.

Here the Examiner is drilling into the components of a scene and their .NET fields and properties. You can also see the Find Selected Script menu in action. (Click on the image to enlarge.)