@BindView(R.id.adView) AdView mAdView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        MobileAds.initialize(getApplicationContext(), getString(R.string.ad_unit_id));
        mAdView.setAdListener(null);
        if (!Constants.IS_FREE_VERSION) {
            mAdView.setVisibility(View.GONE);
        } else {
            mAdView.loadAd(new AdRequest.Builder().build());
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        mAdView.destroy();
    }

    @Override
    protected void onPause() {
        mAdView.pause();
        super.onPause();
    }

    @Override
    protected void onResume() {
        super.onResume();
        mAdView.resume();
    }