Apple first released its Siri voice assistant with the iPhone 4S, and since then it's had overhauls and tweaks to keep it competing with Microsoft's newbie, Cortana, and Google's Google Now.
Cortana is great, but we all know her developers had a lot of help following in the footsteps of Siri, which literally set the tone for voice assistants with its slightly sarcastic, always witty responses to the questions of its teenage operators.
There's some hidden gems on Siri just waiting to be discovered by iPhone owners, and here's some of the best.
Ask him/her "Do you obey the three laws of robotics?" and her answer doesn't expound on the sci-fi master's laws (A robot may not injure a human being, A robot must obey the orders given to it by human beings, A robot must protect its own existence, to be brief).
Instead it answers: "OK, I think the three laws are: 1. Clean up your room, 2. Don't run with scissors, 3. Always wait half an hour after eating before going in the water."
Siri loves to show off, so ask if she knows what planes are flying overhead. Surprisingly, she knows.
The film director's movie Her, about a man who falls in love with his AI operating system, has been acclaimed as a moving work of genius. Not according to Siri. Ask "Siri, are you Her?" and her response is a little harsh: "No. In my opinion she gives artificial intelligence a bad name."