Google has released its new Duo app in the UK, giving FaceTime, WhatsApp, and other video-calling apps a run for their money.

Duo, which was unveiled at Google's I/O developer conference in May 2016, is free to use and enables 1-to-1 video calls. It relies on your number, lets you reach people in your phone’s contacts list, offers end-to-end encryption, and has nifty features like Knock Knock, which allows you to see live video of your caller before you answer. And it's super easy to use, because the app's interface is ridiculously simple.

The new app is already available in the UK version of the Google Play Store for Android devices and should also be available in Apple's App Store for iOS devices. Another part of the attraction of Duo is that Google built in the capability to stay online and connected even when you're on a slower network; the video quality is reduced "gracefully" to ensure that calls aren't disconnected.

Duo is rolling out for Android and iOS now and will soon be live across the globe. If you want to know more about how it works, check out Pocket-lint's hands-on with the app, where we tell you how to get started with it, place video calls, and manage preferences, and more.