IMA SDKs make it easy to integrate multimedia ads into your websites and apps. IMA SDKs can request ads from any VAST-compliant ad server and manage ad playback in your apps. With IMA client-side SDKs, you maintain control of content video playback, while the SDK handles ad playback. Ads play in a separate video player positioned on top of the app's content video player.
For more information, see the documentation at https://developers.google.com/interactive-media-ads/docs/sdks/android/v3/.