(Telecompaper) Google has released a simple video calling application called Google Duo for Android and iOS devices. Designed as a no frills rival to Facebook Messenger and Apple's FaceTime, the app was first announced at Google I/O in May and will begin to roll out in 78 languages over the next few days. To get started, users simply need to download the app and instantly begin a video call with a single tap of the face of the person they want to call. Contacts without Duo can be invited over SMS with an app download link. For video calls on the go, Duo will switch between Wi-Fi and cellular data automatically without dropping the call, said Google.