Machine That Goes "Ding"
Machine (The Day of the Doctor). I get the machine isn't called anything more specific in The Day of the Doctor, but there's still no real reason for the title to be capitalised this way.
Talk about it here.
A Machine That Goes "Ding" was a machine that the Tenth Doctor used to detect Zygon DNA.
Besides lighting up when in the presence of a Zygon, the machine could microwave frozen dinners from up to 20 feet and download comics from the future.
The Doctor thought the machine identified Elizabeth I as a Zygon, but it had in fact detected that her horse was one. (TV: The Day of the Doctor)
Behind the scenes
It resembled the Timey-wimey detector from Blink in many ways, being made of a bunch of random objects, making a "ding" sound, and being able to remotely prepare food.
