

Due to iOS limitations, the app has to be open for this to work on an iPhone. This works best on Android, where it automatically displays the video of the incoming call. Knock Knock makes video calling more spontaneous and welcoming, helping you connect with the person before you even pick up.

To make calls feel more like an invitation rather than an interruption, we created a feature in Duo called Knock Knock which lets you see live video of your caller before you answer, giving you a sense of what they’re up to and why they want to chat.

The app lets you preview incoming video calls before you answer them via a featured called ‘Knock Knock’. I love the simple interface with just a giant ‘Video Call’ button at the bottom, along with avatars of people you can call. It works with your phone number and doesn’t require a Google account. Google Duo is a pretty simple and straightforward video calling app. Today, the search giant has released Google Duo into the wild, both for Android and iOS. In Android, iPhone Google Releases Duo - A Simple Video Calling App for iOS and Androidīack in May this year, Google announced two new apps for messaging and video calling - Allo and Duo.
