On June 14 2013 Microsoft release Office Mobile for iPhone. Currently Office Mobile is only available in the US iTunes store. The app is free as long as you have an Office 365 subscription if you do not you will need to sign up for one in order to use the app.
I personally think that the fact you can now get Microsoft Office on a mobile device such as the iPhone is great as it will allow users to edit all of their documents on the go. Sure there have been applications like Documents To Go and other solutions like that. They can sometimes work well but in my experience they are at a disadvantage because sometime you lose some of the styling of the document. But now that Office is officially available for iPhone this should no longer be a problem.
I quickly tried out the app and it works exactly as you would expect. Whenever you save a file you save it to your SkyDrive. In case you don’t know what SkyDrive is the simplest explanation is that it is a program that will create a folder on your computer and anything you save in it you can access via the internet or via another computer or device you have setup with SkyDrive.
As long as your files are saved in SkyDrive you can access them pretty much anywhere. Another advantage is that you are not limited only to SkyDrive. For example if you get an email with a document you can chose to edit it with Office Mobile. Once you are done you can save it into your SkyDrive or just simply use the share function and email the file back.
Office Mobile includes Word, Excel and PowerPoint.
There is no word yet on when it will be available in Canada or when it will be available for Android. There have been rumors that it will come out in fall 2014 for Android.
Here is a quick promo video for Office Mobile
If you want to explore this more in depth on the features go to http://blogs.office.com/b/office365tech/archive/2013/06/14/office-mobile-for-iphone.aspx



