Textastic is a text editor designed for iOS programmers that provides you with multiple features. The utility offers you support for more than 80 types of markup languages and source codes, comes with a simple, nicely-designed interface, and gives you access to plenty of editing settings for designing the iOS applications you need.
You can paste snippets of code from other Mac apps, attach comments, evaluate math expressions, merge lines, and much more. All of the aforementioned tasks can be completed by going to the main menu of the program and selecting the preferred editing option.
The program also gives you access to plenty of font and text editing settings (line wrapping, text encoding type, tab width, and many others). You can also select the preferred output settings for HTML, CSS, XML or XSL syntax from the Preferences menu of the program.
However, there's a popular Apple product on the Mac App Store called Xcode which comes without a price tag, offers you dozens of useful features, and is intuitive.
With that being said, I don't think it's worth buying Textastic when you can use the aforementioned Apple application without paying a buck.
v1.1 [Apr 28, 2013]
New:
• tabs: you can now open several files in one window
• window size and position is now saved and used when creating new windows
• added shortcuts for hide status bar and symbols
• the text editor now supports VoiceOver
• added SASS/SCSS syntax highlighting
Fixed:
• File type registration is now less aggressive: on some machines, Textastic replaced the default app for files it shouldn't, like for example HTML files. It was also shown in the "Open With" menu for image files.
• The open panel is now non-modal instead of modal: you could not quit the app or go to other windows while the open panel was shown.
• fixed double click and drag text selection
• fixed file permission issues when the syntax definition is changed from the status bar
• implemented Cmd-Delete and added support for more Emacs shortcuts: Ctrl-K, Ctrl-O, Ctrl-T
• soft tabs: backspace didn't work as expected
• custom code completion files are now loaded from the correct location
• fixed a crash when creating template files
• some other minor bug fixes
