Personal Assistant Prompt Form UI

Thoughts on contextual options for when a chatbot avatar could be invoked from a mobile app.

I notice many chatbot user assistance on laptop UI can be launched from a chat icon visible the lower left of the screen (Intercom, HubSpot, etc) and that when active is interacted with in the context of the screen behind. But on mobile apps, the equivalent chatbot experience is provided by a chrome-level or menu level option (via text or voice) that then launches a NEW tab, and context of the screen is lost.

I'm looking for an affordance in the UI where the avatar or icon for the conversation 'floats' in a way similar to the desktop browser experience, like for example using a + 'Add' icon. The idea is the icon launches a smaller in-context conversational dialog with the screen behind it, in the same tab, but I have yet to find research indicating for/against. Anyone been on that journey of contextual chatbot on mobile app UI?