Google Duo, a new video chat app that works exclusively on phones, is getting released today. I've been using it for about a week and I can tell you that it's fast, easy to use, and devoid of complicated bells and whistles. You tap on the face of the person you want to call, they answer, and you have a one-on-one video chat going. Nobody who uses this app can say that Google didn't achieve its goal of creating a video chat app that's relentlessly, explicitly designed solely for phones.

That effort is so single-minded I can't decide if it's timid or bold.

First, a bit about how Duo works. It's available on both Android phones and iPhones. When you sign up, the app checks your phone number from your SIM and then sends you a confirmation text. That's the whole setup process — there are no accounts to create nor friend lists to maintain. It's tied directly to your contacts list and your phone number.

That's great for simplicity, but bad if you want to use Duo on anything other than your phone. It's also unable to make conference calls, put Hangouts-style funny pirate hats on your head during a call, or offer just about any other fancy feature you might expect from a video conference app.

"We thought 'amazing on mobile, nothing on desktop' was the better approach."

Duo's radical simplicity is by design, says vice president of Google's communications division, Nick Fox. "By being laser-focused on mobile," he says, "it enables us to just make sure that we were doing a great, wonderful job on that case. ... For us, we thought 'amazing on mobile, nothing on desktop' was the better approach."

There is one feature in Duo that feels genuinely new: it's called "Knock Knock." When you receive a call on Android (it doesn't work on the iPhone), your entire screen starts showing the live video from your caller before you even answer. It lets you see who's calling — and lets the caller make funny faces to try to entice you to answer. Google's promo video for Duo emphasizes it heavily:

In my testing, Knock Knock worked very well — and it has the added benefit of making the call start immediately. The video call is already running the nanosecond you swipe up to answer it. "Instead of the call starting with frustration and confusion," Fox says, "you start with a smile because you know it already works." I don't know about the smile, but I do know that Duo calls started without all the "Hello, are you there?" that I typically experience with most other video and audio calls.

For those worried about people hijacking their screen with a video feed while they're at dinner or a meeting, a few notes to ease your mind. First, Knock Knock only works with people you already have saved in your contacts — so random people won't show up. Second, you can block a caller if you like — but take note that since Duo doesn't have its own independent friends list, blocking a caller on Duo blocks them everywhere. Last, you can turn the feature off entirely if you don't like it.

Google also has done a lot of work on the back end to make things feel immediate. It's based on WebRTC, with some added technical underpinnings to make the call automatically ratchet the quality up or down depending on your connection quality. It's even able to maintain the call when you switch from Wi-Fi to cellular. After a very brief hiccup, the call just keeps on going.

I mostly tested Duo on a Nexus 5X (running the latest Android Nougat Beta), where call quality was mostly good — better on Wi-Fi, but never so bad that it dropped completely. On the iPhone 6S, call quality was equally good. However, because Google doesn’t have the same ability to integrate on iOS as it does on Android, there are a few hassles: no Knock Knock, and you have to unlock the phone before you answer the call.

Duo is the second of the two apps Google announced at its developer conference this past May. The other is the AI-enhanced text messaging app Allo, for which Google hasn't yet announced a release date. That's odd enough, but perhaps not as confusing as Google's overall strategy with communication apps: instead of fixing its unified solution, Hangouts, Google has opted to release two different (but slightly related) messaging apps: one for video and one for text.

Neither app is designed to replace Google's other video and messaging app, Hangouts. Instead, Hangouts will continue to exist with a more tightly focused mission: serving enterprise users, where Fox says we can expect "it will increasingly be more integrated with Google Apps suite." It will still be available for consumers, of course, but those users won't be the focus of future product development.

Hangouts will continue, but with an enterprise focus

And Fox is also not especially concerned that Google is offering a multiplicity of communication apps. He sees Google's products as split broadly into three bands: Allo and Duo for consumers; Hangouts for the enterprise; and services that are more carrier focused — like SMS, RCS, and even the Phone app. Fox believes that consumers simply aren't confused by a multiplicity of messaging apps — whether they're made by Google or not — "People use the apps that their friends are using," he says. And he's excited to see Duo (and, later, Allo) compete with all of them head-to-head.

How Duo will actually compete was (and is) one of my biggest questions. Why use Duo when Facebook Messenger, Snapchat, FaceTime, Hangouts, and any number of other options exist? Is Google going to leverage the massive power of the Android install base somehow? Will Duo be part of the standard suite of Google Play apps preinstalled on the vast majority of Android phones (outside of China)? "We haven't made decisions on that yet," says Fox. "We want to get it out there, see how it does, and then I see distribution as the next step rather than the first step."

When I said up top that I couldn't decide whether Google's strategy with Duo was bold or timid, this is what I was referring to. It's not going to be the automatic default for all Android phones, replacing phone calls in the way that iMessage replaces SMS. Google isn't ready to go there just yet, which feels timid.

Duo has to compete on its own merits

But it's also bold. In this incredibly crowded marketplace, Google is forcing Duo to compete on its own merits. You can invite somebody to use it by sending them a text from inside the app, but otherwise the plan seems to just be to see how it is received in the marketplace. I asked some variant of "how are you going to get users for this thing" no fewer than four times in my hour with Fox, and every time the answer boiled down to this: "We're focused on building great apps that people love and distribution will follow that."

I have no idea if that plan will work: sometimes boldness is just naiveté. But I can't help but respect the clarity of purpose behind the creation of Duo. It's aggressively, obsessively focused on making the best possible mobile experience for video chat, at the expense of all else. He said no to desktop, no to conference calling, no even to allowing the same account to work on multiple devices. For the Duo team, getting "mobile first" right meant demanding it be "mobile only."

Duo does one-on-one video chat very well, which is what Google set out to make it do. The question now is whether or not that's enough.

Google’s Allo and Duo chat apps first look