Easy does it. Microsoft just updated the Windows 10 Mobile Store with a Fluent Design System treatment, and needless to say, these subtle changes looks quite slick.
As spotted, these new UI elements are now part of the mobile operating system.
The most immediate of which is the sliding panel that pops up when tapping the hamburger menu. It is now translucent. You also get a subtle reveal or touch of light effect when you tap any of the items in the list.
This is how things look:
A really beautiful redesign, overall.
But it’s a bit of a shame that Redmond took this long to add this polish in, at a time when the user base of the mobile operating system is shrinking due to the lack of new Windows 10 Mobile hardware and software. The user interface is not completely smooth right now, but is headed in the right direction.
Anyway, you should see this update when running both the Fall Creators Update on your handset, or the Creators Update too. Version 11710.1000.94.0 of the Microsoft Store app is what you looking for.
This little update should be available on all compatible handsets in due time, as will other Fluent Design System elements across the mobile OS.