title: How to make an android app which contains three other apps?
body: <p>How to make an android app which contains three other apps?
  On the main app, the icons of those three apps are displayed and by clicking on an icon, the coresponding app launches.</p>
  
  <p>Like I want to display the icons of facebook, google map and gmail on the main app and by clicking on the facebook icon, facebook opens up.</p>
  
  <p>Should I make a single APK file for all apps? How?</p>