Joshua Naismith

Joshua Naismith was a 21st century Earth billionaire who played a major role in the plans of the newly resurrected Master. He lived in Great Britain and was said to employ a private army and keep a large stable. He was responsible for Neon, a phone advertised on the side of the 200. He also wrote the book Fighting the Future.

Naismith was the creator of Neon, a phone or phone network. At some point while he was famous, in presumably 2009, he released an autobiographical book, Fighting the Future.

After the fall of the Torchwood Institute, he acquired the Immortality Gate, a device of Vinvocci design. He captured the Master and forced him to repair it. He wanted to use it to give his daughter, Abigail, immortality. Instead, the Master used it to turn everyone in the world into a copy of himself, including Naismith. The Master's work was undone by Rassilon, and Naismith and his daughter fled from their mansion and saw Gallifrey about to crash into Earth. Naismith and Abigail were later mentioned as having been arrested for "crimes undisclosed" (likely their involvement in the near-destruction of Earth and humanity), and put into prison. (TV: The End of Time)

Personality
While he was certainly intelligent, Naismith was essentially a vain, arrogant meddler who was out of his depth. (TV: The End of Time)

Behind the scenes

 * "Naismith" is another instance of Russell T Davies reusing names; his earlier Century Falls features a Dr Josiah Naismith.