title: How to detect new apps in an Android device
body: <p>I want to detect when the user installs or deletes an app, and I didn't find a <code>BroadcastReceiver</code> that does this.</p>
  
  <p>In my app, I get the information about the installed apps with the class <code>PackageManager</code>, but I don't want to scan the apps periodically. Is there any <code>BroadcastReceiver</code> that does this? Or any <code>ContentObserver</code>? Is it possible to get a notification that an app has been installed or removed?</p>