Multitasking is all the rage these days. Certainly that’s the case on the iPad, where the recent release of iOS 9 has brought about split-screen multitasking for the first time to choruses of hallelujahs from users and quick revamps of well-established apps. No doubt it’s handy.

Nearly overlooked, though, is a powerful new feature in iOS 9 that makes operating multiple apps on your iPhone an easier, more fluid task than ever before. It’s the “back to” button, and it’ll make the phone’s power users wonder how they ever lived without it. It’s already changing the way I use and view content in my iPhone.

Here’s how it works: You’re working in an app, when all of a sudden you come across a link or another type of content that requires a re-direct to another app. Once you get to that second app, the upper lefthand corner displays text inviting you to go “back to” the first app. When you’re done in the second app, you hit that text and go back to the original app. The old way—double-tapping your home button to find the orignal app—wasn’t awful. This is simply much better.

Here are five ways to use the function to make your iPhone use easier and more enjoyable:

Newsletters

The feature has completely transformed my use of email newsletters—until iOS 9 was released, I hated reading link-heavy email newsletters on my iPhone because the back-and-forth between Mail and Safari was kind of a hassle. (The Gmail app was an exception—it opened a browser in-app.) Now I find it easier to check my newsletters on the bus to work.

newsletter 2

Facebook

Remember when Facebook was one app instead of two (Facebook and Messenger)? Now you can at least use them in sync again: If you want to chat with a friend while on the social media site, you can easily hop over to Messenger, then hop back again.

facebook 2

Scheduling from mail

Hit a link in mail to schedule a meeting; hit the “back to” button to get back to the original mail.

scheduling email 2

Checking push notifications while working

This one was suggested by my friend Jonathan Kealing at Public Radio International, who suggested the ability to check notifications but quickly return to an app made him feel like those notifications were less of an interruption to his flow. “It feels like a ‘pause’ instead of a ‘stop’ to what I’m doing,” he said.

back to from interupting sms

Buy a song you heard on Pandora in iTunes

Then return immediately to Pandora.

pandora 1

There are plenty of other uses, of course—opening social media content in Safari, for example—amounting a nearly infinite combination when you think of all the times you need to shift between apps.

The “back to” button isn’t perfect—the folks at Nielsen Norman Group say the button is nearly too small and “hardly noticeable” as a result. (They’re pretty sure it was a design afterthought.) That doesn’t seem entirely true to me. I’m well into the struggle-with-fine-print phase of life but noticed the button even though it went largely overlooked in the iOS 9 preview stories. Remember: Even in this era of supersized iPhone screens, there’s still only so much real estate. You don’t want this button to overwhelm other elements on the screen. Still, it won’t be a surprise to see graphic improvements to this feature in future iterations of iOS.

But the NNG folks also show precisely why this “back to” button is such a big deal: Research shows that people looking for information on their smartphones interact with 4.6 different apps and launch apps 10.8 times while looking for that information, compared to 2.6 apps and 3.9 launches during an undirected browsing session.

Which means that the smartphone has gotten smarter in iOS 9. Don’t let the lack of notice fool you. The “back to” button is a big step forward.