The iPhone 4S comes with iOS 5. Check out our walk-through demo of all the best features:

The iPhone 4S is the flagship model for the new iOS software from Apple, making it much snazzier once more.

We'll walk you through the big changes to start with - and Notifications is up there with the best of them.

iPhone 4s review

The new system apes Android by using a drop down menu from pretty much anywhere in the phone to let you see all manner of updates, weather news and messages, plus new notifications will now ping across the top of the screen rather than plopping straight into the middle of the screen like before and disrupting whatever you were doing.

It's not revolutionary by any means, but it's well-integrated and makes the whole system feel a whole lot different to iOS 4.

The lock screen is now called into more use than ever before too, with new notifications sitting on top to be easily accessed without needing to mess about inside the phone.

We quickly got to grips with this new system and can see a lot of people really enjoying being able to open the camera quickly too, which you can do by simply double tapping the home button on the lock screen.

The original system we're fans of is also back in full force, with swipable home screens filled with icons for apps, which you can easily sort into folders or edit by long pressing on the screen.

Double tapping the home button will let you see all your open applications, making it easy to multitask on the go, and swiping to the left gets you to the iPod menu to quickly access the controls. It's the closest we get to widgets with this phone, and we're still hankering after more... but that's the choice Apple is making in the face of the widget-laden Android opposition.

We would like to see contextual menus throughout the interface, for instance being able to change the settings for an app without having to jump out of the main menu - we're sure this has to be coming soon in a future release.

iPhone 4s review

As we've mentioned before, the iPhone 4S now comes with the dual-core A5 processor, which means battery life is meant to be better and the rest of the phone should operate even more snappily.

In our tests, we barely noticed that much of a difference in speed with the iPhone 4, as there was never really a problem with opening and closing applications. With the animations still present, it still seems like the iPhone 4S is a little slower than other dual core handsets on the market (although we mean a tiny amount) but in general use it works perfectly.

It's the most intuitive system on the market in our eyes - we're fans of the complexity of Android, but not everybody is a power user and for the person that wants a simple smartphone that's easy to pick up and start using, the iPhone 4S is one of the best.