Rumors of a version of Microsoft Office app for iOS are now gaining more momentum as sources are confirming that Microsoft intends an early 2013 release. Rumors of a Microsoft Office Mobile app for iOS have been flying around as popularity of the iPhone and iPad continues to grow, but only now the actual details are starting to come to light.

The Microsoft Office app for iOS will apparently be free for viewing Word, Excel, and PowerPoint documents that are created with versions of Microsoft Office for Windows and Mac. Editing these documents on the iOS platform is apparently, however, going to cost.

Sources tell us that Office Mobile will require a subscription to Office 365 if you want to edit documents or create documents on your iPad or iPhone. The Office Mobile app will require a Microsoft Office account, even if all you want to do is take advantage of the free viewing functionality.

As far as functionality, sources claim that Microsoft isn’t intending for Office Mobile to be a fully functional Office on-the-go replacement, but instead with the subscription it will offer “basic editing” functionality. Microsoft is also said to be working on an Outlook app for iOS that is rumored to be called “OWA Mobile Client for iOS.” It will apparently offer Exchange 2012 compatibility as well as Lync support. It will, however, be separate from the Office Mobile product and it is unknown if Microsoft intends to market it; though rumors suggest it could be an attempt to offer an Enterprise solution that would work similarly to Good for iOS.

As for Android owners, Microsoft is working on a version of Office Mobile for the Android OS-based products, as well, but that is apparently a farther down the line. A number of sources are suggesting that we will likely see the iOS version arrive as soon as March 2013.