You can send signals and retrieve visitor segments from Audience Manager.

(Required) The setContext() method must be called once in the onCreate() method of your main activity.

Here is the code sample for this method:

@Override 
public void onCreate(Bundle savedInstanceState) { 
  super.onCreate(savedInstanceState); 
  setContentView(R.layout.main); 
  Config.setContext(this.getApplicationContext()); 
}

If you added this method call when you implemented Analytics or Target, you do not need to add it again.