Microsoft's Office 365 app is now available from Apple's iTunes store for iPhones, iPads and iPods.
The cloud-powered, subscription-based software can be obtained if you're in the US: everyone else, including us Brits, will have to wait a while, though probably not for long. The productivity suite is pretty comprehensive, and supports animations, SmartArt Graphics and charts as well as the usual work document stuff. The app is free, though it will only work for those with an Office 365 subscription.
Below is a video of the thing in action.
The 58MB download does allow off-line editing and creation of Word, Excel and PowerPoint files, but they have to be saved to Microsoft's SkyDrive or Sharepoint. The app will work on an iPhone 4, 4S or 5, or a recent iPad or iPod touch, and requires iOS 6.1 or later. It is "optimised for the small screen of your phone", so iPad owners may need a Surface tablet after all. (Surface being Microsoft's answer to the iPad. Now Redmond is porting its software to the Apple slab.)
Synchronising files across multiple machines, so one can resume reading documents or see recently edited work, needs a PC installation of Microsoft Office, although it's hard to imagine anyone stumping up the eight-quid-a-month Office 365 subscription and not having a desktop computer with which to use it. Assuming a desktop is around then the iOS app will pick up documents at the point where they were left by the user.
The Microsoft Office blog has a guide to using the software, but remains silent on when (and if) it might spread to Google's Android. ®