Google Duo

Google Duo
Google Duo is a video chat mobile app developed by Google, available on the Android and iOS operating systems. It was announced at Google's developer conference on May 18, 2016, and began its worldwide release on August 16, 2016.

Google Duo lets users make video calls in high definition. It is optimized for low-bandwidth networks. End-to-end encryption is enabled by default. Duo is based on phone numbers, allowing users to call someone from their contact list. The app automatically switches between Wi-Fi and cellular networks. A "Knock Knock" feature, exclusively available on Android, lets users see a live preview of the caller before answering. An update in April 2017 lets users worldwide make audio-only calls.

Within two days of its release, the app climbed to the number one spot on Google Play's list of free apps. However, it fell to 127th place after approximately one month. Duo replaces Hangouts as part of the suite of Google apps manufacturers must pre-install on Android devices.

About Google Duo
Google Duo was announced at Google's developer conference on May 28, 2016,and began its international rollout on Android and iOS devices starting August 16, 2016.It quickly climbed to the spot as the number one free app on Google Play within two days of its initial release,but it fell to the 127th place after approximately one month.

In an email sent to Android phone manufacturers on October 5, 2016, Google announced that, starting December 1, 2016, Google Duo will replace Hangouts within the suite of Google apps Android phone makers must pre-install on devices, with Hangouts instead becoming an optional app for phone makers to pre-install.!

Google Duo Features
Google Duo video calls are in 720p HD video.It is optimized for low-bandwidth mobile networks through WebRTC and uses QUIC over UDP. Optimization is further achieved through the degradation of video quality through monitoring network quality."Knock Knock", an Android-only feature,shows a live preview of the caller before the recipient picks up, which Google says is to "make calls feel more like an invitation rather than an interruption".End-to-end encryption is enabled by default.Duo is based on phone numbers, allowing users to call people from their contact list. The app automatically switches between Wi-Fi and cellular networks. In March 2017, it was announced that Google Duo would let users make audio-only calls. The feature was first launched in Brazil,with a global rollout in April.