With the launch of Allo, some folks were reluctant to switch from Hangouts due to a number of reasons. If you are one of those people who are still using Hangouts on an iPhone X, youll be glad to know that the app has been updated to support the iPhone Xs strangely shaped display.
The 21.0.0 version of Hangouts bring optimization for Apples display and will no longer show you black bars in the app. The app will now take full advantage of the display and correctly flow up either side of the devices notch in the display.
Much like how the iPhone 5 brought a wider aspect ratio, developers have to redesign apps user interfaces for the new displays. You can grab the latest update to Google Hangouts on the App Store. Google is slowly but surely updating its iOS app catalog to work properly on the iPhone X.
Source | Via