River Song's sonic screwdriver

River Song's sonic screwdriver was given to her by the Twelfth Doctor during their last date, on the Singing Towers of Darillium.

It was the first gift the Twelfth Doctor personally gave to River face-to-face, after seeing that she was using a sonic trowel, which he found "embarrassing". (TV: The Husbands of River Song)

Unbeknownst to her, this version included a neural relay which would save her data ghost for uploading into the main computer of the Library. (TV: Forest of the Dead)

Among its functions, River's screwdriver was capable of increasing mesh densities to over 800%, (TV: Silence in the Library) activating and disabling gravity platforms, slowing the descent of a fall, fixing light bulbs and storing the consciousness of an individual. (TV: Forest of the Dead)