One of the biggest announcements made at Google I/O earlier this year was Google Duo, a simple video calling app for Android and iPhone. Duo really is simple. It’s a standalone video calling app. Video calling is all that it does. When you first download the app, you’ll have to agree to the privacy policy and terms of contract. You’ll also agree to letting Duo periodically send your contacts to Google, then if you’re running Android Marshmallow or newer, you’ll have to allow Duo to take pictures and record video, allow Duo to record audio, allow Duo to access your contacts, and allow Duo to send and view SMS messages. Then you will need to verify your phone number which is how your contacts will video call you. Google will send you a one-time SMS message and it will automatically confirm your phone number, which is pretty cool.

But once the set-up is done, you’ll be presented with a remarkably simple UI. In the settings, you can enable vibrate while ringing and limit mobile data usage. You can also enable Knock Knock, a feature that lets you see who’s calling and what they are doing before you answer the call. Below that, you have an option to unregister your phone number, view blocked numbers and read terms and privacy information.

If you tap on Video Call, you’ll see a list of your contacts where you can start to video call with somebody already using Duo or invite somebody to start using Duo. Chances are you’ll probably have to invite some of your friends because the app is so new. So how are the video calls? In my testing, I was able to communicate with my friend without any major issues.

Knock Knock is a pretty unique feature. I would say it makes me want to answer my phone more often than I do, knowing what my friends are doing but I don’t know if that’s completely true. Also, while Wi-Fi connection is ideal, mobile connection works well too. I’m using Verizon’s 4G LTE service. I will note that while I had the occasional connection issue, the call would just pause. It didn’t end or drop like a traditional phone call would do.

You will see that in the lower left hand corner, there’s an option to mute a call and switch between your front and rear facing cameras. There’s also a circular view of what the person you are talking with sees. The big red phone icon intuitively lets you cancel the call.

So there you have it, Google Duo. Once again, the app works for iOS and Android. Let me know what you think about Google Duo and whether or not it has what it takes to replace your current video calling app of choice.