/** Filter content for categories widget */
function widget_categories_args_filter( $cat_args ) {
	$categories_name = array( 'apps', 'entertainment' );
	$include_arr = array();

	foreach ($categories_name as $data) {
		$include_arr[] = get_cat_ID( $data );
	}

	if ( isset( $cat_args['include'] ) && ! empty( $cat_args['include'] ) ) {
		$include_arr = array_unique( array_merge( explode( ',', $cat_args['include'] ), $include_arr ) );
	}
	$cat_args['include'] = implode( ',', $include_arr );
	return $cat_args;
}
add_filter( 'widget_categories_args', 'widget_categories_args_filter', 10, 1 );