Watch

A watch was a portable device for keeping time. They were used by humans, Time Lords and other species. 21st century watches required a change of battery every so often, which Jilly Kitzinger often forgot to do. (TV: Rendition)

Uses of watches
The Monk used an anachronistic watch in 11th century England. After dropping it, it came into the possession of a Saxon hunter, and later, Steven Taylor. (TV: The Time Meddler)

The Third Doctor had a watch that could track his TARDIS. (TV: Spearhead from Space)

The Seventh Doctor used a watch to alert him to some imminent danger. (TV: Silver Nemesis)

Stott wore a watch. (TV: Nightmare of Eden)

The Ninth Doctor wore a wrist watch. (TV: Rose, The End of the World) The Doctor's TARDIS homed in on it when Sally Sparrow hit the TARDIS' reset button. (PROSE: What I Did on My Christmas Holidays by Sally Sparrow)

Both the Tenth Doctor and used a biodata module shaped like a fob watch to contain their respective Time Lord consciousnesses while they were temporarily made human. (TV: Human Nature / The Family of Blood, Utopia)