Google has Hangouts, a dedicated app that allows users to conduct video conferences and group video calls akin to Skype. The company does not have a one-on-one mobile video chat app. That changed, however, at Google I/O this year, where Duo was showcased. 

Designed to be rival to Apple's FaceTime, Duo is said to be an app that "takes the complexity out of video calling," according to Google's latest Blog post. Precisely how it does so is unclear, but Google notes that to ensure video calls continue seamlessly when bandwidth connectivity and strength is erratic, the resolution of the call will adjust accordingly. 

To that end, Google says Duo will be able to switch between Wi-Fi and cellular data without ever having to drop or reconnect. That should prove quite enticing for users, especially with cellular data prices still steep across many local carriers. Google has also integrated a feature called Knock Knock into Duo. It allows a video call recipient to see what the caller is doing before accepting the session on their end.       

Duo is set to rollout to both iOS and Android devices from today, and is expected to be a fully global release over the next few days, say Google.