Why?

Enables for example a Digital Avatar 

What?

Android service can have constantly visible Qt Quick QML Window. Launched and controller by the service, visible until service is stopped, but does not need Android Activity. Enables overlaying QML view on top of Android views. Transparency possible with root object of QML window.

Where?

In qtbase cause it requires changes to QPA Android Service handling. Extension of View, enables the adding from Service context - under the hood. No public APIs. 

How?

Requires system level privileges (create the BSP image by yourself) or privileges to sign with the system key, can not be used in consumer devices on apps. No private API used, but functional logic needs to be discussed before FF. 

Who?

Should be cross-are discussed.