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 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 (TV: The Power of the Doctor) after they parted company, (TV: Resurrection of the Daleks, The Power of the Doctor) whilst a hologram of the Seventh Doctor made amends with Ace (TV: The Power of the Doctor) after their fall out. (PROSE: At Childhood's End, TV: The Power of the Doctor)

A hologram of the Fugitive Doctor assisted Yasmin Khan and Vinder in reversing 's theft of the Thirteenth Doctor's body. (TV: The Power of the Doctor)