Android 4.4 KitKat is out now

Google's latest iteration of Android, 4.4 KitKat, has officially been released alongside the new Nexus 5 smartphone. The update should roll out to Nexus devices soon and other recent handsets in coming months, but Google has bigger plans for KitKat.

Android 4.4 brings some big changes to the way Google's operating system updates and how it interacts with Google's in-house apps and features. KitKat is an incremental visual update to Android, cleaning up the home screen, removing some superfluous styling and integrating new features. More importantly, the way core apps are delivered means updated functionality should be added to older phones, too, not just recent releases.

One of the most pivotal changes in Android 4.4 is that, by default, Google Hangouts will serve as Android's SMS messaging app as well as delivering video chat and instant messaging (the service previously known as Google Chat). Users will be able to download and select a different messaging app, but Hangouts in Android 4.4 will bring together text and instant messaging seamlessly.

Google Caller ID is a feature that sounds useful, too; whenever you receive a call from a number you don't have in your contact list, the Phone app will cross-check the number with Google Maps to see if a business has it registered. If that's the case, your phone will display the business' name while it's ringing.

More than just visual tweaks and new apps, though, Android 4.4 KitKat is about how Google is able to deliver updates and new features to both new and old smartphones. The software is 13 per cent more efficient in its display usage than 4.2 Jelly Bean and uses 16 per cent less memory, according to Google's Android chief Sundar Pichai.

Because Google has moved to deliver more of its in-house apps, like Hangouts, Maps and Google+, through the Play store, updates that keep these apps competitive and modern are able to be delivered to any compatible phone with access to the store. Even if a smartphone is running an older version of Android, it will be able to use most of the features that are drawing users to KitKat. Google has also said that in 2014, it will give handset manufacturers the choice to ship only a single version of Android, reducing fragmentation.

Android 4.4 KitKat is debuting with the Nexus 5 smartphone, which can be bought now from Google's online storefront. It will roll out to other devices, starting with other Nexus phones and tablets and Google Play Edition versions of the Samsung Galaxy S4 and HTC One, soon, although a concrete time frame has not been set. It will likely take months to make it through to other phone manufacturers and carriers, so you won't see it on your Telstra-, Optus- or Vodafone-delivered Android phone any time soon.