Kodiak PHP - Kodiak PHP can run any PHP code directly (offline) on your iPad, no need for an internet connection.
phpDesigner - Powerful PHP IDE and PHP editor with built-in HTML, CSS and JavaScript editor. Fast. Powerful.
CodeLobster PHP Edition - CodeLobster - Free portable PHP IDE with support Drupal, Smarty, Twig, WordPress, Joomla, JQuery, CodeIgniter, HTML, CSS, JavaScript, AngularJS, CakePHP, Facebook, Laravel, Phalcon, Symfony, Yii
Servo - PHP builder application which uses a combination of a powerful editor and drag & drop to make...
Nova - Nova is an all-in-one productivity tool. With Nova you can freely choose which components to add to your projects and which you need for productivity, without any pre-set template.
PhpStorm - Professional IDE for PHP and Web Developers