Although apps can currently resize to mobile screen sizes, it will not be able to do so on super wide screen phones like Samsung Galaxy S8 and LG G6 . The display format for Samsung super wide screen has an aspect ratio of 18.5:9. LG G6, has an expanded screen aspect ratio of 18:9.
In order to take advantage of the full screen estate UPI (for , say, displaying QR in ImageView) /any app developer need to declare an android.max_aspect <meta-data>element in the app’s <application>element as follows: <meta-data android:name="android.max_aspect" android:value="2.1" />
The android:value refers to aspect ratio (longer dimension / shorter dimension) in decimal form
Recommended aspect ratio is equal to or greater than 2.1
It should also be noted that if the above value is not set, and android:resizeableActivity is not true, then the maximum aspect ratio defaults to 1.86 ~ 16:9 and your app will not be able to take advantage of the extra screen space.