Crea una ventana de dialogo «Acerca de…» personalizado

    <Button
        android:id="@+id/btnAbout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="30dp"
        android:text="@string/strAbout" />

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"    
    android:orientation="vertical"
    android:paddingBottom="0dp"
    android:paddingLeft="0dp"
    android:paddingRight="0dp"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".AboutActivity" >

    <TextView
        android:id="@+id/tvVersion"
        android:textColor="#FFFFFF"
        android:textSize="16sp"
        android:layout_margin="10dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/strVersion" />

    <ImageView
        android:id="@+id/ivLink"
        android:layout_width="match_parent"
        android:layout_height="80dp"          
        android:background="#ffffff"     
        android:contentDescription="@string/strDesc"
        android:src="@drawable/logo" />

    <TextView
        android:id="@+id/tvLegal"
        android:layout_width="wrap_content"
        android:textColor="#FFFFFF"
        android:textSize="12sp"
        android:layout_margin="12dp"
        android:layout_height="wrap_content"
        android:text="@string/strLegal" />

    <Button
        android:id="@+id/btnOk"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_margin="0dp" 
        android:text="@string/strOk" />

</LinearLayout>

<string name="strAbout">Abrir Acerca de</string>        
    <string name="strOk">Aceptar</string>
    <string name="strDesc">jc mouse</string>
    <string name="strVersion">Version</string>
    <string name="strLegal">THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.</string>

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE shape>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle" >

    <corners
        android:bottomLeftRadius="5dp"
        android:bottomRightRadius="5dp"
        android:topLeftRadius="5dp"
        android:topRightRadius="5dp" />

    <stroke
        android:dashGap="0dp"
        android:dashWidth="0dp"
        android:width="1dp"
        android:color="#ffffffff" />

    <gradient
        android:angle="-90"
        android:centerColor="#282828"
        android:endColor="#161616"
        android:startColor="#282828"
        android:type="linear"/>

</shape>

package com.bolivia.about;

import android.net.Uri;
import android.os.Bundle;
import android.app.Activity;
import android.app.Dialog;
import android.content.Intent;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager.NameNotFoundException;
import android.util.DisplayMetrics;
import android.view.Menu;
import android.view.View;
import android.view.Window;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;

public class MainActivity extends Activity {

 Button btnAbout;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);

  btnAbout = ((Button)findViewById(R.id.btnAbout));
  btnAbout.setOnClickListener(
                new View.OnClickListener() {
                    public void onClick(View view) {
                     showAbout();
                    }});
 }

 @Override
 public boolean onCreateOptionsMenu(Menu menu) {
  // Inflate the menu; this adds items to the action bar if it is present.
  getMenuInflater().inflate(R.menu.main, menu);
  return true;
 }

 /**
 * Metodo que crea y muestra la ventana de dialogo "Acerca de..."
 * */
 private void showAbout()
 {
  final Dialog dialog = new Dialog(this);  
  dialog.requestWindowFeature(Window.FEATURE_LEFT_ICON);
  dialog.setContentView(R.layout.activity_about);
  dialog.setTitle("Mi Programa");  
  dialog.setFeatureDrawableResource(Window.FEATURE_LEFT_ICON, R.drawable.ic_launcher );
  dialog.getWindow().setBackgroundDrawableResource(R.drawable.dialog_box);

  //ancho y alto de la ventana de dialogo
  DisplayMetrics displaymetrics = new DisplayMetrics();
  getWindowManager().getDefaultDisplay().getMetrics(displaymetrics); 
  int width = (int) (displaymetrics.widthPixels*0.84);
  int height = (int) (displaymetrics.heightPixels*0.7);
  dialog.getWindow().setLayout(width, height);
  // Información de la versión del software
  PackageInfo pInfo; // obtiene información de la version del software
  try {
   pInfo = getPackageManager().getPackageInfo(getPackageName(), 0);
   TextView text = (TextView) dialog.findViewById(R.id.tvVersion);
   text.setText("Version " + pInfo.versionName);
  } catch (NameNotFoundException e) {
   e.printStackTrace();
  } 
  //Cuando se presione la imagen se abrira una página web
  ImageView ivLink = (ImageView) dialog.findViewById(R.id.ivLink);
  ivLink.setOnClickListener(new View.OnClickListener(){
      public void onClick(View v){
          Intent intent = new Intent();
          intent.setAction(Intent.ACTION_VIEW);
          intent.addCategory(Intent.CATEGORY_BROWSABLE);
          intent.setData(Uri.parse("https://www.jc-mouse.net"));
          startActivity(intent);
      }
  });
  //Boton para cerrar el dialog
  Button dialogButton = (Button) dialog.findViewById(R.id.btnOk);
  dialogButton.setOnClickListener(new View.OnClickListener() {
   @Override
   public void onClick(View v) {
    dialog.dismiss();
   }
  });  
  dialog.show();

 }

}//end: