Apple event – as it happened: New iPhone and Watch prices and release dates revealed as major update includes ECG technology

"Every detail has been thoughtfully considered, and it's just beautiful," Williams says. 

The screens are over 30 per cent larger than its predecessors. This means "every part of the UI has been redesigned."

Series 4 will also allow you to "add loved ones to your watch face" so you can tap on them to connect. 

Essentially, the watch faces are much more customisable than the Series 3.

The Apple Watch does everything, Williams says, from helping you book flights, to literally telling you how to breathe through a meditation app.

And there's new watch faces too, featuring flames and vapor and bubbles. 

"Look how the bubbles splash off the edges," he says. 

The new Apple Watch will also feature a next-generation accelerometer and gyroscope. What does this mean? "Apple Watch Series 4 can detect a fall."

Once detecting a fall, the Apple Watch triggers an SOS feature that allows you to contact emergency services. If no motion is detected for one minute, the watch will automatically contact them for you. 

"Fall detection is a feature that we hope you'll never need," Williams says, "but it's really nice to know it's there."

This isn't the only way the Apple Watch could save your life. Sensors mean it can help detect if you suffer from something called atrial fibrillation. 

According to the British Heart Foundation, Atrial fibrillation is "a common abnormal heart rhythm that happens when electrical impulses fire off from different places in the atria (the top chambers of the heart) in a disorganised way. This causes the atria to twitch, and is felt as an irregular heartbeat or pulse."

Previous versions of the Apple Watch have already helped save lives. 

Earlier this year, we reported on how an Apple Watch might have saved a man's life after it alerted him to the fact that his heart wasn't beating properly.

You can read the full story here: 

Ivor Benjamin from the American Heart Association comes on stage briefly to say how great Apple is. 

Williams comes back to say that the new Apple Watch features have received FDA approval. Queue loud applause.

The COO takes a moment to remind everyone how much Apple cares about its customer's privacy. "All you health and fitness data, it's encrypted on the device and in the cloud," he says, while politely avoiding naming any other tech rivals caught up in recent data scandals. Ahem, Facebook.