Theo wrote:

Andy Burns quoted:

Note that some devices do not allow third
party applications to access their multiple cameras, in which case Open
Camera isn't able to use them

The Samsung camera app uses special proprietary APIs to talk to the camera
on top of the generic Android camera APIs. The Android side works, but
doesn't exploit the full features provided by the camera. This also means a
camera downgrade if you run something other than Samsung's Android on your
phone.

I suppose that's covered by the final sentence, though some phones with
thermal imaging also present that as an extra camera using the standard API.