MeshModifierEditor.cs

using UnityEngine;
using System.Collections;
using UnityEditor;

[CustomEditor(typeof(MeshModifier))]
public class MeshModifierEditor : Editor {

	public override void OnInspectorGUI ()
	{
		DrawDefaultInspector();

		var mm = (MeshModifier) target;

		if (GUILayout.Button("Log")) {
			mm.LogMesh();
		}

		if (GUILayout.Button("Test")) {
			mm.ModNormals();
		}
	}
}