iOS: Editorial is one of our favourite text editors on iOS, because it's incredibly powerful, has lots of customisation options, and allows you to create complex automation schemes. Now, it's on the iPhone too, and it comes with a slew of other improvements.
The biggest change in this update to Editorial is the iPhone support, but it also comes with a whole new redesign, support for Multi-Markdown, TextExpander support, new keyboard shortcuts and new workflow actions. The iPhone version works great on the smaller screen, and it's packed with most of the same features as the iPad version. You can find the full list of new features over on the Editorial site.
Editorial ($8.99) [iTunes App Store]