Duo, Google's FaceTime-like video calling app for Android and iOS, allows users to see video previews of the caller before answering.
Google launched its free cross-platform video calling application for Android and iOS on Monday after the company first announced it in May.
The application is expected to reach a large range of smartphone users as it works on both Android and iPhones, unlike its Apple rival application FaceTime, which is only designed for company devices.
Google says Duo's advantage is that it is simple and available to everyone, even when there is a bad internet connection, while allowing users to see the live-video of callers with the new feature, dubbed Knock Knock, before picking up the call.
"Knock Knock invites you into the moment, making calls feel spontaneous and fun. Once you answer, Duo seamlessly transitions you right into the call," Google explained in its official blog.
The feature, which only works in Android phones, also offers the option of blocking the application entirely to avoid unwanted videos appearing on the screen.
Google manager for Real Time Communications, Amit Fulayö said the the video communication is much better with the new Google app because it removes all the friction and makes phone calls more like an invitation rather than an interruption.
"Duo is all about simplicity and quality. It's all about video calling. There are no frills, no knobs or dials to adjust, it just works," he said.
Besides having the notable features which other video calling applications such as Microsoft's Skype or Facebook's Messenger don't have, the application also offers a reform in Google products, as for the first time the company doesn't require a Google account to sign up.
The company was previously blamed by European Union for skewing the market against its rivals by forcing Android users to download Google applications.
The newly launched app can be found in the IOS App Store and Google Play Store in 78 languages.