The Doctor's main source of tools and gadgetry is his Tardis. The Tardis is used to travel through time and used to get from place to place. This machine has been used and upgraded by every Doctor so far. In the newest episode, number 12, the tardis had exploded which made every other galaxies go super nova and disappear from existence. Only the planet Earth stays in existence because the tardis was still burning because it keeps repeating Rivers trying to open the doors while it is exploding. Then when the doctor sends the Pandorica into the burning tardis when he had realized that the light from the Pandorica can release old atoms that were inside the Pandorica and restore the other non-existant galaxies. For more information... WATCH THE EPISODE (number 12)
The Sonic Screwdriver can practically do anything that the Doctor wants it to do. The Screwdriver can lock and unlock doors, it can destroy weapons. It has the ability to overload or hack any computer system. The Scredriver can also scan people or other species.
The Pandorica (Not an actual tool built or used for the Doctor's purposes):
The Pandorica was built by all of the universal species. Its purpose was to contain the most feared then in all of the galaxies, the Doctor. The Pandorica is a prison for the Doctor so that he would not destroy the universe, even though he would not have anyway. Watch episode #12 to find out more.
Prof. River Song's Time Agent Vortex Manipulator:
A more primitive form of time-travel technology, a vortex manipulator allows the user to travel through time by minimally controllable (and apparently uncomfortable) "hops" through the Time Vortex. The technology is compact enough to be worn on one's person easily, such as the wrist-mounted device in the possession of Jack Harkness, which he obtained during his stint as a Time Agent. The Family of Blood also had one capable of moving a small spaceship. When Jack notes that such technology means the Doctor is not the only person capable of travelling through time, the Doctor disdainfully compares the "space hopper" vortex manipulator to his "sports car" TARDIS. The device also allows travel through space by harnessing the energies of wormholes (such as the Cardiff Rift), as demonstrated by Captain John Hart and Gray in series 2 of Torchwood. As seen in "The Sound of Drums", the Manipulator can also be programmed to teleport its operator (and anyone hanging on) from place to place once the Doctor has used his sonic screwdriver to jump-start it. The Doctor disables Jack's manipulator at the end of "Last of the Time Lords", but Jack figures out how to re-enable it (or at least restore its teleport function) in "The Stolen Earth". In the last episode of the 2008 series "Journey's End" the Doctor once again disables Jack's vortex manipulator with his sonic screwdriver. In the final episode of "Children of Earth", it is revealed that the Vortex Manipulator (or at least Jack's) is indestructible, capable of surviving an explosion that destroyed the Torchwood Three building. In "The Pandorica Opens," River Song gets a vortex manipulator from a black market dealer in order to meet up with the Doctor, the dialogue suggests the manipulator is still on the disembodied hand of a Time Agent. River is able to use it much more accurately than Jack ever could, traveling to where she wants with no apparent problems. Later, the manipulator ends up in the hands of the Doctor who uses it to travel back in time and have the Auton copy of Rory Williams free himself trapped in the Pandorica. As the TARDIS is destroyed, the Doctor uses it to teleport through time, traveling to 1996 to meet up with the resurrected Amy Pond then using it to travel back in time to set the events in motion by giving Rory the screwdriver and leaving young Amy the notes that led her to the Pandorica. After learning River is still alive and is trapped in a time loop in the destroyed TARDIS (an emergency protocol to protect anyone inside), the Doctor is able to teleport into the TARDIS and rescue her. The Doctor later uses the manipulator to travel back in time 12 minutes to trick a Dalek and then pilot the Pandorica into the heart of the TARDIS explosion. After he is brought back from being erased from existence, the Doctor returns the manipulator to River who uses it to teleport away, presumably back to her own time. "http://en.wikipedia.org/wiki/List_of_Doctor_Who_items"
K-9, or K9, is the name of several fictional robotic dogs in the long-running British science fiction television series, Doctor Who, first appearing in 1977. K-9 has also been in a central character in three of the series television spin-offs, the unsuccessful K-9 and Company(1981), The Sarah Jane Adventures (2007–present) and K-9 (2009–10). Although not originally intended to be a recurring character in the series, K-9 was kept in the show following his first appearance because he was expected to be popular with younger audiences. There have been at least four separate K-9 units in the series, with the first two being companions of the Fourth Doctor. Voice actor John Leeson has provided the character's voice in most of his appearances, except during Season 17 of Doctor Who, in which David Brierley temporarily provided the character's voice. The character was created by Bob Baker, to whom rights to the character still belong; consequently, Baker's spin-off series K9, which is not BBC-produced, cannot directly reference events or characters from Doctor Who, though it attempts to be a part of that continuity. "http://en.wikipedia.org/wiki/K-9_(Doctor_Who)"