Add Sub-Pages to Gravity Forms Admin Navigation

If you want to add a page to the Gravity Forms Admin navigation options, add the following code to your theme’s functions.php file.

add_filter( 'gform_addon_navigation', 'create_menu' );
function create_menu( $menus ) {
  $menus[] = array( 'name' => 'my_custom_page', 'label' => __( 'My Custom Page' ), 'callback' =>  'my_custom_page' );
  return $menus;
}

function my_custom_page(){

    echo 'My Custom Page!';

}

This would create a page called My Custom Page that shows text on it that says My Custom Page.