When iOS 8 hits, the notification center is going to be the most important screen in your iPhone. Think about it: Notifications already are the way you know about everything that happens without having to fire up an app. A notification lets you know you have a new email, a new text message, a new Snapchat. (Hi, Tony. Looking good.) But with iOS 8 they become interactive. They're not just simple announcements—or even calls to action—anymore. They are actions in and of themselves. Entirely new windows onto our data. It's nearly impossible to overstate how much this will change the way you use your phone.

Interactive notifications will spur all sorts of new behaviors. (And yes, Android already has interactive notifications, but the ones in iOS 8 look to go beyond what KitKat can do.) Some of these will be simple, like the ability to reply to an email or text message. But they're powerful in that you can do this without quitting whatever you're already doing. And this interactivity is not just limited to system apps. Third-party developers can take advantage of this new capability as well, so you could comment on something on Facebook, respond to a tweet, or even check in on Foursquare. But others are going to be radical, stuff we haven't imagined yet. Once developers begin to really harness what interactive notifications can do in iOS 8—and they will—it's going to cause one of the most radical changes since third-party apps. With the advent of iOS 8, notifications are the new interface frontier.

You probably don't think much of them, but the lowly notification has already had some pretty dramatic effects. It has wrought massive changes in telecom, for example, where it made possible the rise of messaging. (After all, how would you even know you'd received a message without a notification to buzz your phone?) WhatsApp and Snapchat and other services that rely on real-time, if asynchronous, communication would be useless without the ability to tell people to pick up their phones. We give messaging apps the credit, but ultimately it is notification that caused SMS to shed billions in revenue.

Companies like Facebook and Twitter already rely on notifications to drive usage and growth in the developing world. That presents a model for how they can be used in developed markets. If you're the first person in your village to sign up for Facebook, you aren't going to find much reason to come back again. So the notification that your neighbor just joined becomes hugely important. And that act of messaging someone almost has to be done from the operating system level. It's just the most efficient way. After all, someone coming online for the first time may not have an email address. If your user base is at all significant, sending SMS alerts to everyone is cost prohibitive. And while SMPP (the Short Message Peer-to-Peer protocol) is an option, it requires direct deals with carriers—which won't happen on a global level without a massive business development footprint. Notifications are what make your app grow.

And, really, WhatsApp and Facebook and Twitter and the like have been building on a system where notifications were a one-way street. Sure, you could see them, but you couldn't really act on them. That's where iOS 8 is going to fundamentally change how you interact with your phone. And when you consider what kinds of radical things people have done with static notifications, interactive ones are really exciting.

Image: Courtesy of WUT

Take WUT, an app that is already using the notification center as an interface unto itself. WUT is an ephemeral, anonymous short-form messenger that lives in the notifications center. That's a buzzword mouthful, but explaining what it does is easy: it uses notifications to deliver anonymous messages. WUT connects with your Facebook friend graph, and lists the messages your friends have sent in the notification center. Once something drifts out of your notifications, there's no way to see it again. There's barely even an app interface—launch WUT and all you see is a posting function. There's no history. No cards to scroll through. Pretty much everything happens in the notifications center.

After using the app for a few days, I felt like WUT had taken me by the collar and shaken me, something I'm not alone in. It advances a radical notion that isn't obvious at first: The notification center is the interface.

Not surprisingly, WUT's cofounder Paul McKellar (who previously co-founded Square) is looking ahead to what iOS 8 notifications will mean. "We've been pouring through the public docs on Apple's website, but it looks like a lot of app interaction could be moved to the lock screen," he told WIRED in an email. "The notification stuff is awesome for us, and many other apps. Anything you can do with a single button now doesn't require you to open the app at all."

"The Today view is great because devs can extract at-a-glance views: Bitcoin price, last 5 Instagram photos, today's sales in Square, maybe even check in on foursquare, " McKellar notes. "The buttons can also be individually secured by requiring you to unlock your phone, which is nice if you are doing anything with money, or privacy like accepting a Venmo money request. "

Apps changed everything by countering the messiness of the Web. They proved a focused experience beats a broad one on a small screen. But as they've proliferated, navigating to them individually to perform simple tasks has become cruelly inefficient.

When we can interact with our data in short bursts via notifications, we make remarkable efficiency gains, especially on tasks that we perform again and again. Apps will become more about information and communications; we're going to think of them as services instead of as windows onto our data. The things that can make best use of single click efficiency will soar. A whole new world is up there waiting for us at the top of the screen. We just need to pull it down.