Google Duo provides you with a one-to-one video calling app designed to be simple and reliable.It features a user-friendly interface that allows you to immediately start using it, simply pick a contact and go. You can screen your video call by viewing the caller before you decide to answer via the live preview feature. Video calls can even be made between Android and iOS and whether you are on Wi-Fi or not.Google Duo also allows you to make voice-only calls if video calling is unavailable. Data charges apply where applicable.