The iPad is a fantastic device for media work like video and photography, and has become the go to tool for many to browse the web, but most would agree the iPad wouldn't be a programmer's first choice when they want to do some coding. Textastic might change that view.
Textastic Code Editor is $13.99 from the App Store, and available for both the iPad and more recently, the iPhone.
I haven't used the iPhone version, but on the iPad it is a decent word processing tool, and more importantly, a very capable code editor which almost legitimises using your iPad for doing dev work.
Textastic also allows you to create your own syntax definitions and themes.
Writing on the app is designed to ease the fact that there are no physical keys on the iPad, although it works perfectly well with a third party keyboard accessory.
The extensive code library, which is updated quite regularly, lets the user autocomplete syntax tags.
Start a <div> and you can jump to your next element with the tap of a button, and the app will close off the first tag you started.
Textastic has a custom keyboard which makes common programming symbols easily accessible at the top of the standard qwerty layout. A scroll wheel hovering over the text edit layer is used to quickly highlight words, or it also lets you skip lines.
While not a professional developer myself, I have been able to update and make small changes on my self-hosted Wordpress site by connecting the app to my FTP server.
Like most modern code editors, Textastic comes with a web preview button which lets you see what your changes look like in a live environment.
Textastic can also sync files from WebDAV servers, download them from Dropbox, or transfer them directly onto the iPad using iTunes file sharing.
The price tag is quite steep when compared to other apps in the market place, but very few have the feature depth and ease of use that Textastic provides.
Price: $13.99 from the App Store