checkout_extensions_list

gistfile1.php

<?php

function extensions_list($extensions = array()) {

	$extensions['guestcheckout'] = array(
		'name' => "Guest Checkout",
		'link' => "http://domain.com",
		'image' => plugins_url() . '/mypmethod/images/icon.png',
		'description' => __("My Payment Method for the Shopping Cart plugin.", 'mypmethod'),
		'slug' => 'mypmethod',
		'plugin_name' => 'mypmethod',
		'plugin_file' => 'mypmethod.php',
		'settings' => '?page=link-to-settings-page',
	);
	 
	$titles = array();
	foreach ($extensions as $extension) {
		$titles[] = $extension['name'];
	}
	 
	array_multisort($titles, SORT_ASC, $extensions);
	return $extensions;
}

add_filter('checkout_extensions_list', 'extensions_list', 10, 1);

?>