LoadTexture.cs

using UnityEngine;
using System.Collections;
using System.IO;


public class LoadTexture : MonoBehaviour {
  [SerializeField] string fileName = "icon";
	
	[SerializeField] GUITexture gui;
	
	IEnumerator Start () {
		
		string path = "file://" + Path.Combine( Application.streamingAssetsPath , fileName);
		
		using(WWW www = new WWW(path))
		{
			yield return www;
			Texture2D tex2d =  www.texture;
			tex2d.Compress(true);
			gui.texture = tex2d;
		}
	}
}