I am using the Google plus api to show the +1 button on my app. I am building against the latest version of Google play services(8.3) and testing on Nexus 9(updated to marshmallow and 8.3.01 Google play services)
But it still shows the old design of the +1 button.
How do I display the new design. 
Code I am using in the layout file :
<com.google.android.gms.plus.PlusOneButton android:id="@+id/plus_one_button"
xmlns:plus="http://schemas.android.com/apk/lib/com.google.android.gms.plus"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:focusable="true"
android:minHeight="24dp"
plus:annotation="inline"
plus:size="medium" />
Can you check your activity to ensure you have initialized it this way:
Where: - URL is the address of the Google page to be +1'd
Plus I am assuming you have done all of this https://developers.google.com/+/mobile/android/getting-started before you got here because you are seeing the required result.