Google Duo is a video and audio calling app made by Google, similar to Facebook's WhatsApp, Apple's Facebook, and Microsoft's Skype. It is free to use and works across both iOS and Android devices. It uses your number, reaching people in your phone's contacts list, and offers end-to-end encryption. Its Knock Knock feature will allow you to see live video of your caller before you answer. Google Duo supports group video calls with up to 8 people for free. So it is particularly nice for small groups like families and friends to get together during the special time of coronavirus. Key Features Simple interface: the app's interface is straightforward, and you just pick a loved one and jump right in, making video calling easy. The highest quality video calling app: provide reliable video calls with excellent video quality, whether you're on Wi-Fi or on-the-go. Knock Knock: you can know who's calling before you pick up with a live video preview. Video messages: you can leave your friend a video message for them to call you right back if you fail to connect them. You can share your beautiful moment with a video message. Voice calls: make voice-only calls when you are not available for a chat over video. More Duo has a feature named Low-light mode that will make you more visible to the other end of the video when you are in poor-light surroundings. You can disable this feature under the 'Settings' menu. Google Duo supports group video calls for up to 8 people; you can create a group by tapping on 'Greate Group' at the bottom of the Google Duo screen and select the contacts you want to add. Duo for Web allows you to video call with your families and friends without having to join the app on your mobile devices. Try out the new Duo for Web.