title: Calling an extrenal application
body: <p>How can I call an external application from my application?</p>
  
  <p>E.g: I need to call <code>Shazam</code> (application) from my app. 
  I can see the package name of the application in the <code>logcat</code>.</p>
  
  <p>will that be useful for any purpose?</p>