title: Android - Customizing ads
body: <p>I have developed an Android App and want to add some custom ads in it. I know that I can make a fragment and attach it to the layout but what about changing the ads frequently?
  For e.g. I have two Images (of ads) and want to change every of them in 5 minutes. How can I do that?
  Also I do not have any idea to put interstitial ads. Any help is appreciated. I am a beginner in this field</p>