is a one-to-one video calling app. It is designed to be cross-platform so that both Android and iOS users can chat, which is not the case with the app's rival FaceTime. Duo works with both WiFi and mobile connectivity, so you can chat with your loved ones at home or on-the-go. It also includes a feature, called Knock Knock
, which lets you preview any chat before answering (as long as the caller is in your contacts).
Google Duo also works with iPod touch devices running iOS 9.0 or later.
Google Duo for iPhone is also available on Android