void OnGUI()
    {
#if UNITY_ANDROID
        // Disable user input for GUI when impressions are visible
        // This is only necessary on Android if we have disabled impression activities
        //   by having called CBBinding.init(ID, SIG, false), as that allows touch
        //   events to leak through Chartboost impressions
        GUI.enabled = !CBBinding.isImpressionVisible();
#endif

        GUI.matrix = Matrix4x4.Scale(new Vector3(2, 2, 2));

        if (GUILayout.Button("Cache Interstitial"))
        {
            CBBinding.cacheInterstitial("Default");
        }

        if (GUILayout.Button("Show Interstitial"))
        {
            CBBinding.showInterstitial("Default");
        }

        if (GUILayout.Button("Cache More Apps"))
        {
            CBBinding.cacheMoreApps();
        }

        if (GUILayout.Button("Show More Apps"))
        {
            CBBinding.showMoreApps();
        }
    }