FaceTime, in its mass popularity, has always been a favorite app of Apple products that Google had not paralleled in its own apps.
As of recently, however, Google has produced Google Duo, an app similar to FaceTime with very simple and to-the-point characteristics. The app does not require a Google account to activate but rather mandates your phone number and permission to your contacts instead
Duo’s home screen includes a face cam, video call button and settings tab. The video call feature allows you to call anyone who also has the app or invite anyone in your contacts to download the app as well.
Google Duo also has a feature called Knock Knock. If your Knock Knock is turned on, the person calling may see you as they attempt to call though this feature can be turned off at any time. The user may also turn off vibrations while it rings and limit the amount of mobile data it uses when in calls.