In PowerApps there is already a phone form factor Org Browser template.
This post is about creating an Org Chart type app for the tablet form factor and or an app you can embed in a web page.
Online && SharePointAccess
Part 2 of Building a Theme Component
In this post I will demonstrate saving to the Theme preferences to SharePoint and how to add a layer of Security to the using an Azure Active Directory Security Group.
Add a theme component to add custom styles to your app in design mode or even allow your users to style your app and save their preferences.