The app will act as a central hub for all your Microsoft Office needs, replacing the current My Office app. Open it up and you'll get access to all the Microsoft Office productivity apps at the top of the window, making it easy to switch back and forth. It will also show you the documents you've recently worked on, and it comes with a search function so you can find documents that aren't immediately onscreen.
Microsoft says it's modeled this experience after the Office.com, which also acts as a central hub for but for web users.
Microsoft has been redesigning its range of Office software lately, including a recent update to the Outlook app for iOS.
The new Office app is available to select Windows Insiders now and will roll out to all Windows 10 users soon. The app is free and compatible with any Office 365 subscription, Office 2019, Office 2016 and Office Online. It'll be available through the Microsoft Store, and starting in summer 2019 it'll come preinstalled on new Windows 10 devices.