SmartCopier is an editor extension plugin for Unity. It expands Unity's system of copying components from one object to another, and allows the user to do it in a quicker way, with extra options. You are able to select copy and paste multiple components at once, as well as picking and choosing which serialized properties of these components should or should not be copied. Its is very simple, but effective in its execution, and can potentially save developers who make extensive use of Unity's default component copying feature a lot of time.
You can buy the asset in the Unity Asset Store here for a mere €2.23.