https://www.theverge.com/2018/8/6/17655520/google-digital-wellbeing-beta-now-available-dashboard-app-timers-wind-down

The various Digital Wellbeing features that Google revealed last spring — a dashboard to show your smartphone usage habits, app limit timers, and a “wind down” mode to help you focus on going to sleep — are not included in today’s release of Android 9 Pie. But if you have a Pixel device and you’ve already installed the latest OS update on it, you’ll be able to try out those software tools ahead of their official launch sometime this fall. The beta starts right now.

Google says that trying out these Digital Wellbeing features does not require joining the Android beta program; you can continue running a stable version of Android 9 Pie while testing the Dashboard, app timers, and wind down. So that’s pretty great.