it is used in the term, "how do ya' like them apples?" basically meaning, "what do you think about that?" it is a phrase that intends to piss people off.

In World War I, something called a Stokes gun fired mortars resembling apples with a stick in them, so they were often referred to as Toffee Apples.

In the movie Rio Bravo in 1959, a guy tosses a hand grenade and says "How do ya like them apples?"

that.

When you throw a Dell apple at somebody.