Adds a window for Unity that lets you easily switch to scenes in your build settings

SceneSwitchWindow.cs

using UnityEngine;
using UnityEditor;
using UnityEditor.SceneManagement;

public class SceneSwitchWindow : EditorWindow
{
	[MenuItem("Window/Scene Switch Window")]
	public static void ShowWindow ()
	{
		SceneSwitchWindow win = (SceneSwitchWindow)EditorWindow.GetWindow(typeof(SceneSwitchWindow));
		win.titleContent.text = "Scene Switch";
	}

	void OnGUI ()
	{
		int sceneCount = EditorBuildSettings.scenes.Length;
		for (int i = 0; i < sceneCount; i++)
		{
			if (!EditorBuildSettings.scenes[i].enabled)
				GUI.enabled = false;

			EditorGUILayout.BeginHorizontal();

			string sceneName = System.IO.Path.GetFileNameWithoutExtension(EditorBuildSettings.scenes[i].path);
			if (GUILayout.Button(sceneName))
			{
				EditorSceneManager.OpenScene(EditorBuildSettings.scenes[i].path);
			}

			if (GUILayout.Button("+", GUILayout.Width(32f)))
			{
				EditorSceneManager.OpenScene(EditorBuildSettings.scenes[i].path, OpenSceneMode.Additive);
			}

			EditorGUILayout.EndHorizontal();

			GUI.enabled = true;
		}
	}
}