Intune "App Configuration Policy" for Android - What/Where is the Configuration Designer?

I wanted to configure apps on Android for Work.

 

So I end up at this link:

https://docs.microsoft.com/en-us/intune/app-configuration-policies-use-android#use-the-configuration-designer

 

Which talks about using the configuration designer or JSON to set the app configuration "settings" (Key/Value pair?)

 

Big problems with this whole section:

1. Does not provide a link to this "Configuration Designer"
2. Does not document which Microsoft MAM or MDM  1st party android apps have support App configuration (I think only Managed Browser?)
3. Does not point to curated list of Intune MAM enabled 3rd party apps that support configuration

 

But really - where is this "Configuration Designer"...

 

-Neil