The beauty of an App Store is that you sometime stumble upon neat little gems and Textastic (iTunes Store link) certainly is one for me. Despite the hard to pronounce name, the app is amazing if you are a programmer that wants to edit text files either locally or on remote servers. The app supports FTP, FTPS and SFTP connections, with a password or a private key.
It also supports Dropbox and it does syntax highlighting for a ton of different file types and programming languages. The app is well done, well designed and, in my opinion, well worth the 10$ price tag.