myWebView.setWebViewClient(new WebViewClient() {
    @Override
    public void onPageFinished(WebView view, String url) {
        myLoadingView.setVisibility(View.GONE);
        myWebView.setVisibility(View.VISIBLE);
    }
});
myWebView.loadUrl(...);

myWebView.setWebChromeClient(new WebChromeClient() {
    public void onProgressChanged(WebView view, int progress) {
        myLoadingView.setText(progress+"%");
    }
});

super.setStringProperty("loadingDialog", "Wait, Loading...");

public class MainActivity extends DroidGap {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        super.setIntegerProperty("splashscreen", R.drawable.splash);
        // Display a native loading dialog.  Format for value = "Title,Message".
        // (String - default=null)
        super.setStringProperty("loadingDialog", "Wait,Loading Demo...");

       super.loadUrl("file:///android_asset/www/index.html");
      }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <ProgressBar
        android:id="@+id/progressBar1"
        style="@android:style/Widget.ProgressBar.Horizontal"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:maxHeight="10dip"
        android:minHeight="10dip" />

</LinearLayout>

final Activity activity = this;
private ProgressBar progessBar1;

View footer = View.inflate(getContext(), R.layout.mainshop, null);
root.addView(footer);

progessBar1 = (ProgressBar) findViewById(R.id.progressBar1);

this.appView.setWebChromeClient(new WebChromeClient() {

        public void onProgressChanged(WebView view, int progress) {
            activity.setProgress(progress * 1000);
            if(progress < 100 && progessBar1.getVisibility() == ProgressBar.GONE) {
                progessBar1.setVisibility(ProgressBar.VISIBLE);
            }
            progessBar1.setProgress(progress);
            if(progress == 100) {
                progessBar1.setVisibility(ProgressBar.GONE);
            }

            Log.d("Progress", progress+"");

         }
    });

$.mobile.showPageLoadingMsg();
$('.ui-loader h1').html('<h1>Saving ... <span id="ui-loading-extra"></span>');

$('#ui-loading-extra').text(progress  + '%');