To begin with, Doc² simply handles .doc formatted files. It can't handle .docx files, which have been the standard for Microsoft Word since Office 2007 for Windows and Office 2008 for Mac. Sure, you can save Word files in the Office 97 - 2004 or XP formats to load into Doc², but that takes an additional step. Quickoffice, on the other hand, can read and write the old and new file formats. If you want to create or edit a spreadsheet file, Doc² isn't going to do the job for you. Instead, you'll need to purchase a separate app -- Sheet² [US$3.99, iTunes Link]. Want to write a plain text file? Nope, you can't do it in Doc².
So far, I've touched on what Doc² can't do. But what about what Doc² can do? To its credit, Doc² has a number of Mac and Windows connectivity options available. To begin with, Doc² features integration with the MobileMe iDisk, so it is possible to open documents that are stored in an iDisk folder or save new documents onto iDisk. That's something that a number of iPhone apps offer, so iDisk integration alone is no big deal. However, Doc² also offers integration with Google Docs as well. I was able to open documents that were stored in Google Docs, as well as create new documents and save them to my Google Docs account.
Like many of the other word processing apps for iPhone, Doc² makes it quite simple to move documents to and from Mac and Windows machines. This can be done through a web browser on any platform, simply pointing the browser to the iPhone on the same Wi-Fi network, or from a Mac by selecting Go > Connect to Server and entering the iPhone's IP address. Password security can be enabled for the network connection to protect your local (iPhone) files from prying eyes.
Creating a new document is as easy as opening a folder -- either Local Files (on the iPhone), Google Docs, iDisk, or another WebDAV folder -- and then tapping on the traditional iPhone plus sign button. Doc² asks for a name for the new document, then opens a blank page. While you might expect the iPhone keyboard to appear when tapping on the blank page, it doesn't. Instead, you need to tap on a keyboard button. This may seem counter-intuitive, but actually makes sense. You type the document, then get the keyboard out of the way so that the various formatting tools located at the bottom of the data entry screen can be used to make the document look good.
The leftmost button below the blank page holds the various text formatting tools, such as bolding, italicizing, or underlining text, changing the text and text background colors, or the font style and size. Doc² provides six standard type faces -- Arial, Times New Roman, Georgia, Helvetica, Trebuchet MS, and Courier New -- and 21 different sizes from 6 to 72 point.
The next button provides writers with alignment choices -- left, middle, right, and justified alignment. Next, there's a tool for indenting a paragraph or removing an indentation. Another button sets up bulleting and numbering, while another allows users to insert tables or graphics. The graphics are chosen from the iPhone's photo library.
If you want to create a table in your document, Doc² is capable of creating tables up to 20 columns wide and 50 rows long. However, there's a practical limit to how many columns you can squeeze onto a page, so I'm not sure how the ability to create 20 columns could really be useful on the iPhone's small screen.
Doc² also provides a full find capability, although it's not possible to do a global find and replace. As a writer, I like Quickoffice's ability to provide word and character counts. That's something that could easily be added to Doc² in a future update.
There are plenty of other word processing apps in the App Store. Quickoffice has been around for years in the handheld device world, and although the iPhone version is still lacking some capabilities (no Power Point editing, for example), it's a strong contender. Documents To Go Premium [US$14.99, iTunes Link] from DataViz is the most Office-like app of the bunch, but requires a special Mac or Windows app for file syncing and cannot access files stored in iDisk or on Google Doc.
If you're considering an app like Doc² to do some limited word processing work, it might be a good idea to do some expectation management first. Realize that you're going to be writing or editing documents on a device with a small screen, that you'll need to tap your letters in rather than be able to touch-type, and that you'll never see the document in your iPhone editor exactly the way that you'll see it in Microsoft Word. With all of those limitations, if you still decide that editing-on-the-go is a major need for you, Doc² might be a good, relatively inexpensive choice for you.
Be sure to take a look at the gallery below for some screen shots of Doc² in action.