Microsoft is believed to be working on a new Cortana-powered app for Windows Phone that will serve as the user's central hub for all his Microsoft Office documents.

The app, called Work Assistant, has been published on the Windows Phone Store but is not yet available for download. However, an Italian Windows blog has gotten hold of the new app and has posted screenshots of the app in action.

Windows Blog Italia says Work Assistant will use Cortana to carry out simple voice commands such as search, open, edit, and share documents as well as more complex tasks such as "open the presentation yesterday" or "email this file to this person." Just as Google uses "Ok Google" and Apple has "Hey Siri," Work Assistant will reportedly respond to "Office."

Sources cited by The Verge's Tom Warren, who conducted a little digging about Work Assistant, say the app used by Windows Blog Italia is the private beta version available only to Microsoft internal testers.

The goal is to eventually integrate the Cortana-based Office assistant into Windows for phones, tablets, and desktop PCs. In the future, Work Assistant will also make its way to Office for iPad and Android, says The Verge, which affirms an earlier statement made by Julie Larson-Green, chief experience officer of Microsoft's Applications and Services Group, that Cortana will be eventually worked into the Office apps for iOS and Android.

Long-time Microsoft follower and ZDNet correspondent Mary Jo Foley says Work Assistant was developed by Microsoft's Digital Life + Work group, which operates under Larson-Green's ASG. She also believes Microsoft founder Bill Gates may have some involvement in the development of Work Assistant.

In a Reddit Ask Me Anything (AMA) held last week, Gates said he was working on "personal agent" project that helps people organize their files and choose what to work on, although he did not provide more details.

"One project I am working on with Microsoft is the Personal Agent, which will remember everything and help you go back and find things and help you pick what things to pay attention to," Gates said. "The idea that you have to find applications and pick them and they each are trying to tell you what is new is just not the efficient model - the agent will help solve this. It will work across all your devices."

Work Assistant requires at least 2MB of space and works only on Windows Phone 8.1 at the moment. The full version will become available first for Windows 10 across all platforms before Microsoft rolls out Work Assistant for iOS and Android.