Component always on top

I need to insert in my ionic angular app a page/component that should stay always on front on any other pages of the apps, modals included.

This page is a chat, that could be fullscreen or minimized (by css), when minimized it take a small draggable div on the lower right corner,
the user can continue navigate the App but the component minimized should stay always visible never covered by other components.

Thanks in advance