Google Duo now allows people to call phones that don't have the Duo app installed. This feature will only work for Android phones.
Those that receive the calls don't even have to be registered for Google Duo to be able to receive the calls.
App Preview Messaging
The new feature that allows other Android users to receive calls from those using Duo is Google's App Preview Messaging. This allows the users to send a message through the app to any contacts even when that contact doesn't have the app installed.
When receiving the call, users have the advantage of seeing who is calling them with Google's "knock knock" feature. This feature allows those receiving calls to see a live video feed of the caller before they choose to answer the call.
Once the call is finished, a prompt will appear on the screen asking if they would like to install the app — if they do not have installed.
There are limitations to the app. Those on iPhone will not be able to enjoy this feature. Those who are receiving the calls will need to have their phone number added to their Google account.
Google is trying to pry attention away from competitors such as Whatsapp. It hopes to become the default video calling app in the Android community. Using this new feature and Duo coming preinstalled on certain Android phones, Google is trying to attract more attention to Duo. Google has a ton of messaging apps, but it now seems to be pushing Duo, and Allo, its text-based messaging app, to the forefront.
Google still hasn't addressed the new update to the app publicly. This means people still aren't sure about the app's limitations. All of the features are being discovered through tests of what the app can do for the moment.
Allow Quietly Updates
App Preview Messaging quietly works through the background app Google Play Services. This lets users receive messages through apps even if they don't have them installed. Back in 2016, this service and Allo were both launched. When the service was released, there was a promise of the service becoming open to all developers of messaging apps.
App Preview Messaging has been used by Allo since it was launched. The messages, however, did not look like Allo and lacked many of the features that come with the text app.
App Preview Messaging only works with other Google accounts that have the user's phone number registered.