All singing, all dancing is an idiom meaning "full of vitality", or, more recently, "full-featured". It originated with advertisements for the 1929 musical film The Broadway Melody, which proclaimed the film to be "All talking all singing all dancing".[1]
Recently, the idiom has come to be used to describe high tech gadgetry such as smartphones, indicating that the product is very advanced, or has an abundance of features. For example, from a 1995 article in The Daily Telegraph[1]:
"Satellites as small as a box of cornflakes can be launched at little cost by riding piggyback with larger satellites. A handful of these 'microsatellites' would be used instead of a single all-singing all-dancing 'platform' bristling with instruments."
"All Singing, All Dancing" is the title of a ninth season episode of the animated television show The Simpsons.
The phrase also appears in the 1996 novel Fight Club, and the 1999 film based on it, in which the character Tyler Durden excoriates his disciples, "You're the all singing, all dancing crap of the world."