Kodiak PHP - Kodiak PHP can run any PHP code directly (offline) on your iPad, no need for an internet connection.
LINQPad - A scratchpad for C#, F# and VB code including Linq queries.
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
Snippet Compiler - Authors description: "Snippet Compiler compiles snippets."
WritePHPOnline.Com - WritePHPOnline.Com is an online site that enables you to write code in PHP and view its output.
Linqer - Linqer is a SQL to LINQ converter tool.