The phone’s shell is responsible for how apps are displayed. Even the smallest improvement to how apps render can have a positive impact on all Librem 5 applications – enabling more of the rich application ecosystem in PureOS to work better on mobile.
A typical app on the Librem 5 takes up 360×648 logical pixels. When an app enters fullscreen, the phones UI hides away, thus giving the app access to 360×720.
To unhide the shell, simply swipe from the top or bottom where the bars would be.
The UI is still accessible whenever it’s needed, but it’s now smart enough to know when to get out of the way.
For non-convergent desktop apps you can employ UI scaling, which will allow you to run most FOSS apps on the Librem 5 in non-docked mode.