There’s an updated (November 2019) PowerApps and Flow Licensing Guide. There are only small changes to this guide since the main changes to PowerApps and Flow licensing happened in October 2019. Find the changes detailed in the Change Log on page 21, and note that this guide isn’t yet updated for the renaming of Flow to Power Automate. Get this latest guide here: http://bit.ly/PowAppLGNov2019.