A free Microsoft Office app that will allow document viewing plus a premium version that will enable editing and other features could be available at the beginning of 2013.

The free version will require users to have or to set up a Microsoft Office account and is expected to launch on the Apple App Store first before becoming available for Android users later in the year.

Office Mobile, as it is being called by tech blogs, will enable Word, PowerPoint and Excel document viewing, but by signing up for an Office 365 subscription users will also get basic editing functions on their smartphones or tablets -- however, don't expect the full functionality of the Office suite.

The Verge, which broke the story on Wednesday night, claims that the iOS version of the app will arrive in late February with the Android version expected to land in May 2013 -- only five years after the first Android phone was launched.