public static IGooglePlayObbDownloader GetGooglePlayObbDownloader()
    {
        if (m_Instance != null)
        {
            return(m_Instance);
        }

        if (!IsDownloaderAvailable())
        {
            return(null);
        }

        m_Instance = new GooglePlayObbDownloader();
        return(m_Instance);
    }
        public static bool Check()
        {
            string content       = "odd touched";
            bool   need_download = false;

            IGooglePlayObbDownloader googlePlayObbDownloader = GooglePlayObbDownloadManager.GetGooglePlayObbDownloader();

            if (googlePlayObbDownloader == null)
            {
                content = "Use GooglePlayDownloader only on Android device!";
                return(false);
            }

            string expPath = googlePlayObbDownloader.GetExpansionFilePath();

            if (string.IsNullOrEmpty(expPath))
            {
                content = "External storage is not available!";
            }
            else
            {
                string mainPath = googlePlayObbDownloader.GetMainOBBPath();

                if (string.IsNullOrEmpty(mainPath))
                {
                    need_download = true;

                    content = "need download OBBs";

                    googlePlayObbDownloader.FetchOBB();
                }
            }
            Debug.Log(content);

            return(need_download);
        }
 void Start()
 {
     m_obbDownloader = GooglePlayObbDownloadManager.GetGooglePlayObbDownloader();
     // YOUR PUBLIC KEY HERE (this is spellbook's public key)
     m_obbDownloader.PublicKey = "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAmbXD+JdeFn2dp41yRJHOXPIztz9/9oftnX0Se1rWOXqGtEW5uxXXX6ERHb9F8k8MetgtmIndwj4hl9nCKb6O0soBTY09DdUrwNmPemU16SgiCCxR3l0TavcgdBGyrMrRsqCbG+D4Utl8cbFA+nQ42B0ZV2Lof1JI6XB1AfvMwGZHGBu6Rz5D+2QzbEukWxlw+Rgu+Ei5uVeSY98FYxy0Ki8odoImAOigfgzm1y+/Tw/MivXjXatWsr5XWxiozAYGBjC6Bj14NbBzp7I51zetlfYdUBIc2uX5hAK/6vQ0ic7KgGXwPHOayolZRZ6fZc3mw347qxIqOzEQrFHfBo98mQIDAQAB";
 }
 void Start()
 {
     m_obbDownloader           = GooglePlayObbDownloadManager.GetGooglePlayObbDownloader();
     m_obbDownloader.PublicKey = ""; // YOUR PUBLIC KEY HERE
 }