Holo-Doctor

The Holo-Doctor, (PROSE: Infinite Requiem, TV: The Power of the Doctor) also referred to as the holo-me by the Thirteenth Doctor, was an interactive AI hologram, (TV: The Power of the Doctor) that both the Seventh Doctor (PROSE: Infinite Requiem) and the Thirteenth Doctors used. The hologram could take the form of different Doctors. (TV: The Power of the Doctor)

History
The Seventh Doctor once gave Bernice Summerfield a "simple, interactive hologram" of himself that projected from a small pyramid, originally intending to give it to Ace before she left them. Benny considered its realism perfect apart from haziness around the edges, and mentally referred to him as the "holo-Doctor" or "h-Doctor." He wore the Doctor's brown coat, hat, and usual umbrella. (PROSE: Infinite Requiem)

The Holo-Doctor was later used by the Thirteenth Doctor to assist her in thwarting the Master's Dalek Plan. The Doctor had planted hologram implants on Yasmin Khan, Tegan Jovanka and Ace, allowing the hologram to appear in close proximity to any one of them. A hologram of the Fifth Doctor made amends with Tegan Jovanka, reminding her that he never forgot her after they parted company, whilst a hologram of the Seventh Doctor made amends with Ace after their fall out.

A hologram of the Fugitive Doctor assisted Yasmin Khan and Inston-Vee Vinder in reversing the Thirteenth Doctor's forced regeneration and bore witness to resulting "forced degeneration" before deactivating. (TV: The Power of the Doctor)