Google Duo is the highest quality one-to-one video calling app*. It's simple, reliable and works on both iOS and Android phones. Features: Simple interface Pick a loved one and jump right in, with a simple interface that brings video to the forefront. Knock Knock See the caller before you pick up with Duo's live preview feature. The highest quality video calling app* Experience faster and more reliable video calls whether you're on Wi-Fi or on-the-go. Cross-platform Video call all your friends across Android and iOS with just one simple app. Audio Calls Make audio-only calls to your friends when you can't have a video call. *Based on Signals Research Group technical study comparing video degradation time over 3G, LTE, and WiFi. **Data charges may apply. Check your carrier for details.