After countless months of "will they" or "won't they," Microsoft has finally conceded to give iOS users their very own version of Office in app form. Most iOS users, that is. Assuming they want it in the first place, which is no safe assumption given its many, many limitations.
The first thing to keep in mind is that Office for iOS literally isn't for everyone. To access the app, you need a $100 per year Microsoft Office 365 subscription, and there's no iPad version yet. That's going to be a hard sell for anyone who isn't already knee-deep in the exciting world of Excel under any circumstances. It's especially daunting given that Office for iOS is going to be a companion at best.
When you first sign in to the app, you'll have the option of opening an existing file from your SkyDrive or creating a totally new document or spreadsheet (there's no PowerPoint creation option, for obvious usability reasons). There are even some actually pretty convenient templates to pick from for both. But that's where things start to get a little wobbly.
Those templates are convenient, sure. But a large part of that convenience also lies in the fact that they give you a few tools that you'd never be able to reproduce on your own otherwise within the app. In Word, for instance, the outline template is great as long as you only have two main points to make. Try to add to the list, and things start to get a little messy.
And while there are certainly some neat things you can do within the app, for the most part, creating a totally new document from nothing is a clunky process you'll want to avoid except in the most extreme of circumstances. What sorts of extreme cases might warrant that, though, I cannot begin to imagine.
You won't be able to add any new images, format paragraphs, change fonts, or basically do anything else you might expect of a basic word processor. And getting around what you can do isn't exactly a pleasant process. Instead of iOS's native hold-to-copy-and-paste function, you have to double-tap on a word. Which would be fine, except that this version is glitchy at best—half the time we weren't able to expand the highlighted section without a few rounds of furious tapping.
Basically the most you can expect to do is some light editing of documents you've spent way more time on elsewhere. Anything more intensive, wait until you get back to your laptop.
Excel actually ends up being the most usable corner of Office for iOS, which is either thoughtful of Microsoft or a slap in the face because honestly, spreadsheets is what works? And it does! You can shade cells, create a variety of charts, auto-adjust how numbers are displayed, and sort by the method of your choosing.
Presumably, the entire world of Excel formulas is also at your fingertips. Overall, there will be far more occasions where you'll find yourself wanting to whip out a new Excel document, if not solely for its ability to effortlessly take on complicated calculations. We even found ourselves wishing that Microsoft had dumped the all-inclusive app in favor of perfecting and adding functionality to a standalone Excel app (if not the whole lineup). But with how severely limited you are in everything else, that wouldn't quite line up with the point Microsoft is apparently trying to make.
As far as PowerPoint goes, unless you've made a grave, fire- and/or failworthy error, stay away from the editing feature. You're going to end up doing more harm than good. Unlike Word and Excel, you can't create any new presentations, but you are free to edit the text on the various slides. The problem with that, though, is that you can't adjust text box sizes, fonts, font size, color, layout, etc. If whatever you're writing ends up spilling over its allotted space, you're effectively screwed.
Of course, if you just need something to look at while you're giving a presentation or in order to prep yourself, you'll be perfectly happy with what you've got available to you. You'd also be perfectly happy viewing the slides in Office's mobile web app. But the app does let you rearrange the slide order. So I guess there's that.
One nice thing about the Office for iOS, though, is that you can comment on specific words, paragraphs, cells, what have you, making it particularly useful for shared files. Because not only are you able to pull things from your SkyDrive, but you can also access your various SharePoints. For a student or someone whose job relies heavily on collaborative documents, this feature alone could definitely make the app worthwhile. Then again, if collaboration is your thing, why aren't you using Google Docs?
Generally, though, Microsoft's reluctantly released app has no desire to let you rely on mobile for your Office needs. There's also no iPad optimization—Microsoft's pushing people to the web app for that—which is unfortunate since a larger surface would make its limited features far more pleasant to work with.
In other words, you're not going to want to shell out for an Office 365 subscription for mobile alone. It's a way to access and make bare-bone edits to your files, but that's it. And with that being said, it's probably only going to appeal to those people that actually need a basic companion to Office's more fully functional form. And anyone in that category is already going to have a subscription anyway.