Editor script to make a grid of sprites, aka, poor man's tilemap

MakeGridOfSprites.cs

using UnityEngine;
using UnityEditor;

// @kurtdekker
// cheap and cheerful grid-of-sprites maker
// this is an editor-time application
// it assumes you will further manipulate this grid and DIRTY AND SAVE THE SCENE
// be sure to drop this into an Editor folder!

public class MakeGridOfSprites : EditorWindow
{
	public int across = 15;
	public int down = 10;
	public Sprite sprite;
	public Vector2 spacing = new Vector2( 1, 1);

	[MenuItem("GameObject/Create Sprite Grid")]
	static void Init()
	{
		MakeGridOfSprites window = (MakeGridOfSprites)EditorWindow.GetWindow(typeof(MakeGridOfSprites));
		window.Show();
	}

	void OnGUI()
	{
		GUILayout.Label("Make a grid of sprites in scene - @kurtdekker", EditorStyles.boldLabel);

		across = EditorGUILayout.IntField("Tiles across", across);
		down = EditorGUILayout.IntField("Tiles across", down);
		sprite = (Sprite)EditorGUILayout.ObjectField( sprite, typeof( Sprite), true);
		spacing = EditorGUILayout.Vector2Field( "Spacing", spacing);

		if (GUILayout.Button( "Build the grid!!"))
		{
			var parent = new GameObject( "MakeGridOfSprites-Parent").transform;

			for (int j = 0; j < down; j++)
			{
				for (int i = 0; i < across; i++)
				{
					var pos = new Vector2( i * spacing.x, j * spacing.y);

					// center it
					pos -= new Vector2( across - 1, down - 1) * 0.5f;

					string tilename = System.String.Format( "Tile ({0},{1})", i, j);

					var tile = new GameObject( tilename);
					tile.transform.SetParent( parent);
					tile.transform.position = pos;

					var spriteRenderer = tile.AddComponent<SpriteRenderer>();
					spriteRenderer.sprite = sprite;
				}
			}
		}
	}
}