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 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)

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