Can the Apple Watch work without an iPhone?

Update: With the cellular Apple Watch 3 available you can now do more than ever without tethering your Watch to your iPhone, but even without Apple's latest wearable there are plenty of phone-free Apple Watch features.

With the arguable exception of the cellular version of the Apple Watch 3, the Apple Watch isn't designed to replace your iPhone just yet. In fact, it depends on it.

Many Apple Watch apps are really just displays for things running on your iPhone, and some key features aren't available if you aren't paired to an iOS device.

For example, the original Watch doesn't have a GPS receiver, so if your phone isn't around you can't track the distance you've travelled beyond measuring steps.

GPS has been included in the Apple Watch 2 and Apple Watch 3, but even they don't have their own cameras, so while you can use them as a viewfinder for your phone they don't have the ability to snap anything by themselves.

That doesn't mean the Apple Watch is a dumb terminal, though. It has its own processor, sensors and on-board storage, and we're increasingly seeing stacks of innovative apps as developers are discovering the possibilities.

Here are the key things you can do with any Apple Watch model, even when there's no iPhone for it to talk to - after the initial setup on the handset is complete that is.

Pay for stuff

Once you've set up Apple Pay via the Apple Watch app, you'll be able to use the Watch to pay for things in shops.

The app creates a unique token that's stored on the Watch to use as a card number - allowing you use Apple Pay even when you're away from your phone. To pay, simply wave your watch at the Apple Pay-compatible terminal and let the built-in NFC (near-field communication) radio do its thing.

Get on planes or go to the movies

Apple Wallet is on the Apple Watch, so anything already stored in it - aeroplane boarding passes, electronic tickets and anything else scannable - should work just fine without your iPhone.

Sadly, not all firms have embraced this, so we're still often wandering around with pockets and purses full of plastic, but we're gradually seeing more things go digital.

Listen to music, audiobooks or podcasts

The Watch has its own storage space, some of which is available for music - so you can use the Watch's built-in Bluetooth to pair with a pair of wireless headphones and get music on the move.

Naturally you won't be able to stream music from the likes of Spotify or Apple Music without an internet connection, which means being in Wi-Fi range or using an Apple Watch 3 cellular model, but there's more than enough internal storage for a run, a workout or a short commute.

Open doors

One of the smoothest features we saw at the Apple Watch launch event was SPG Keyless, a feature that enables Apple Watch users to unlock Starwood hotel rooms without anything as old-fashioned as a key.

According to Starwood, the keys work via Bluetooth Low Energy and are popped up by the iPhone app as push notifications the day before you check in.

The same idea could of course work with any other kind of Bluetooth-enabled smart lock, so it's possible we'll see Apple Watch-compatible locks for your home, garage or gym locker.

Track your fitness

The Apple Watch doesn't need to be paired with your phone to monitor your heart rate or workout: it can store that data and sync it to the Health app when you get back from your run, cycle or trip to the gym. There are also various third-party fitness apps available, such as Strava.

Control your Apple TV

Apple's Remote app has been ported to the Watch, and like its iOS sibling it enables you to control your Apple TV via the magic of wireless radio.

You can also use it to control iTunes on your computer.

Do watch things

Hardly a surprise, this, but time-related functions such as the alarm, stopwatch and timer don't need a phone to function.

What iPhone-free features do you think we'll see from app developers? Let us know in the comments.