One-to-one video calling with Duo

Google’s one-to-one video-calling app is designed to make video-calling super simple.

Duo not only runs on Android but also iOS. Plus, you don’t need a Google account; sign up with just your phone number.

An innovative feature, ‘Knock, Knock’, let’s you see a video preview of the other person before they can see you.

All calls with Duo are end-to-end encrypted.

The app is very simple by design, without any additional connections to messaging or other Google services.