TouchQode (Bonus) download
As an added bonus we have TouchQode, which is an editor just for smartphones. It’s currently only available for Android, but you can subscribe to be notified about the iPhone release. For a smartphone editor, it has some really good features such as syntax highlighting, the ability to run (simple) scripts, an integrated FTP client, file syncing and more. TouchQode really gives the the ability to code anywhere you go!
No iPhone app (but coming soon)