A common feature between macOS and Windows is to add an overlay image on top of the application icon.
It would be useful to have a cross platform API for this. If the system doesn't support this feature natively, the implementation can blend the two icons and replace the application icon, faking the effect.
|For Gerrit Dashboard: QTBUG-94009|
|428678,20||Add QGuiApplication API to set a number-badge in the Dock/task bar||dev||qt/qtbase||Status: MERGED||+2||0|