Google Duo now lets you call your contact who don't even have the app
by Geekboots | Fri, 12 Jan 2018
Similar like Google Allo, Google is rolling out a feature in Duo to call your contacts with those who don’t even install the app. As per a close observation of Reddit user, if you have a latest Android version 8.1 you can video or audio call to your contacts. It works almost exactly like a normal Duo call, including the Knock-Knock feature. It works through a feature of Google Play services called App Preview Messaging, which launched alongside Allo and now it's also available for Duo.