gistfile1.php

<?php

class Page extends SiteTree {

	private static $db = array(
		'ShowInFooter' => 'Boolean'
	);

	private static $defaults = array(
		'ShowInFooter' => 1
	);

	/**
	 * @return FieldList $fields
	 */
	public function getSettingsFields() {
		$fields = parent::getSettingsFields();

		$showInFooter = CheckboxField::create('ShowInFooter', 'Show in footer');
		$fields->insertAfter($showInFooter, 'ShowInSearch');

		return $fields;
	}

}