https://phys.org/news/2018-08-android-version-pie-monday-pixel.html

Google names its Android versions after sweet treats, such as Marshmallow. Google chose Pie in part because an upcoming feature called Slices will try to offer slices of information from your favorite apps without opening them.

You'll be able to start testing features aimed at improving people's digital well-being, including a "wind down" mode that will fade the screen to grey at a designated time to help you disconnect before bed.