The iPhone Duo doesn't officially come out until tomorrow, but on the Bloomberg "Power On" podcast , Apple oracle Mark Gurman is already reporting on the iPhone Duo 2 and the iPhone Duo 3.

Early reviews for the iPhone Duo are out now (Mashable Senior Editor Stan Schroeder said in his Duo review that it's the "most interesting iPhone since the first one"), and some reviewers have complained about its reliance on Touch ID. Many iOS users have gotten used to Face ID in recent years, but the Duo uses a Touch ID fingerprint sensor instead.

But according to Gurman, Bloomberg's consumer technology managing editor, prototypes of the iPhone Duo 2 with an under-display FaceID sensor are already circulating inside Apple.

"I’m told there are iPhone Duo 2 prototypes at Apple already that have an under-display Face ID sensor and camera on the outside screen, so that is something we could see," Gurman said on his "Power On" podcast .…