A small tool which measures the distance (in Unity units) between two game objects in your Unity editor viewpane.

Instructions:

Unzip the DistanceBetweenTwoObjects 7zip archive.

Place the DistanceBetweenTwoObjects.cs script into your Assets > Scripts folder.

Drag a copy of this script onto each game object in your heirarchy you wish to calculate the distance from.

Then simply drag the second object into the resulting inspector slot on the first objects' script inspector.

Distance will render in editor viewpane.