One of the big changes on the iPhone 5S is one that will come to a number of other devices: iOS 7. However this is clearly the flagship device for the new operating system, and it shows off the UI redesign superbly.

The Retina display is clearly calibrated to make best use of the explosion of color on offer, and the flatter icons look painted onto the screen.

For those that missed the iOS update, you'd best gird your loins if you're not a fan of colour all over the place. iOS 7 is a lot brighter, cleaner and sleeker than its bloated predecessor, but it does look like Jony Ive has dipped into his crayon pot a few times.

But don't think this is a negative: we're fans.

The colors on offer are fun, fresh and most importantly distinctive, giving a real unique feel to iOS 7 that other platforms might not have. Photos, Safari and Music are all changed, as well as a host of other apps too, and while some have labelled them 'childish', they're clearly indicative of the new style Apple is looking to create.

iPhone 5S review

What we do find frustrating in iOS 7 and its previous iterations is the dependence it has on the settings menu, with various app controls all housed here instead of within the apps themselves.

It's annoying if you're in the Facebook app for example and want to adjust the notification settings, you have to exit the app and navigate to the setting menu instead.

Look beyond the UI though and you'll see that the iPhone 5S is much easier to use, which is impressive for a phone that was already market-leading in its simplicity.

iPhone 5s review

Dragging upwards from pretty much anywhere on the phone will open the Control Center, giving access to the music player, brightness, quick apps such as a timer, torch and calculator as well as allowing you to switch on and off elements like the Wi-Fi and Bluetooth.

Yes, it's a notion that's been part of Android for a number of years, but it's been done in a way that feels a lot more solid and intuitive, never changing with notifications so you can easily trust that when you need a torch you can get to it easily.

iPhone 5S review

That said, the torch was an odd area of the Control Center. Whenever lifting up the tab to access said function, you'd always need to wait a second or two before being able to hit any of the app quick icons. Not a huge problem but one that quickly got tiring. It's like the whole drawer needs a second to boot up.

There's also a new notification area that can be accessed by dragging downwards. Thankfully unlike the Control Center, this can be customized: you don't need to have to look at stocks or your upcoming meetings or lack of social engagements if you don't want to, but there's always information on the weather there, which is nice when you realise you'll need a coat.

This is also the place where you'll get any missed notifications, be it a call, message or that jacket on eBay you were looking to buy and it's ending soon and should you put down some more money, no, but you've done it anyway and phew you didn't win because it would have been too expensive but it was nice are there any others oh there's one on Buy It Now, that's really nice I shouldn't but... PayPal.

You know, the usual things you can do with a phone.

iPhone 5S review

Both of these areas are nicely designed too - with translucency that allows you to see very vaguely through to the rest of the phone, giving the whole handset an air of completeness, a phone that's able to connect within itself and not fall apart when a new app rolls into town.

Multi-tasking has been given an overhaul with iOS 7, and gone is the bar which appeared at the bottom of the display when you double tap the home button.

The double tap action now sees the screen you're viewing minimised to a thumbnail in the center of the screen, and a horizontal list to the right of it made up of small panels of all the other apps running in the background.

The layout reminds us of the multitasking menu on HTC's Sense UI, and you can scrolling through the various applications, swiping up over thumbnails to close certain applications.

iPhone 5S review

We're not overly keen on the new design as the interface does break things up when flicking between apps, where on the iPad you've got the great five finger swipe to move between open apps – could this have not been repeated on the iPhone?

There's obviously some other new features, as well as some old favourites. For instance, a long press on any app will engage the editing mode for the home screen, meaning you can uninstall anything you fancy (as long as it's not hardcoded by Apple) and drag and drop it onto another icon to make a folder.

The folder system was a great idea from Apple, and it's been improved with iOS 7, allowing users to dump more in one folder and just swipe through it to see more apps.

It's not a big thing, but show it to any iPhone user now and they'll smile at such an important fix. Who wants 'Games 4' anyway?

The rest of the phone is mostly a cosmetic upgrade - there are some important performance tweaks, such as on the internet browser and camera UI, but iOS is really a lick of exceptionally powerful and much-needed paint, keeping the raw power and integration that Apple prides itself on while taking some of the clever ideas from other smartphones on the market and making them its own.