Google what?

Duo. It’s a new one-on-one video calling application that Google showed off at its developer conference a few months ago. Now it’s being made available to consumers.

Hasn’t this already been done?

Lots of times. Skype has been knocking around for a while, and FaceTime is a big thing for Apple users. WhatsApp is also introducing video calls.

Right. So what’s different about Duo?

It switches between wifi and mobile data apparently seamlessly, so if you lose one connection, it will drop you on to another. And if the app detects a bad connection, it will adjust the bandwidth to try to stop the call dropping, freezing or turning so badly pixellated, you could be talking to a complete stranger. Speaking of strangers, you can block people too.

There’s also the Knock Knock feature, which allows you to see a clip of who is calling before you pick up the call/.

Not so sure about that Knock Knock thing. It seems a bit creepy.

It only appears if you have the caller saved as a contact, so there will be no nasty surprises. You can switch it off too.

Isn’t it doomed to fail? It’s a bit behind the times.

Not necessarily, When Google launched Gmail, it wasn’t the first to offer an web-based email app. But it was easy to use and offered lot of free storage, so people signed up. Now Gmail has more than a billion active monthly users. Not bad for a latecomer.

Of course, it’s not a given that it will succeed. Look at Google +, for example.

What are the advantages of using it?

It’s cross-platform - well, iOS and Android at least. All you need is a phone number; you don’t even have to have a Google account. Plus it’s separate from Google’s many other products.

What are the downsides?

It’s separate from Google’s many other products. You can’t send a text chat through it, you can’t make audio only calls - for now, the feature is apparently on the way - and you can only use it on one device at a time, unlike FaceTime. And unlike Apple’s product, it’s only for phones at the moment, so you can’t use it on your PC either. You can download it to tablet but on an iPad it will still have the dimensions of an iPhone app, and on Android, you’ll have to install the APK and allow your device access to “unknown sources”. That can be a security risk.

Anything else?

I’m not sure that the name will become a commonly used thing. We Google things, FaceTime people, but Duo?

It’s still video calling though.

Yes. And with all the awkwardness that brings. But if that’s your thing, now you have another option.