Sometimes you see something on the Internet and think to yourself, “there is absolutely no way that works as advertised.” As great as it would be to lose 100 pounds without changing your diet or exercising at all, it’s a pretty safe bet that the pills you saw advertised in a Google AdWords ad on some mommy blog aren’t going to deliver on that ridiculous promise.

To be perfectly honest, I was just about as confident in PureGear’s Smart + Buttons glass screen protector as I was in those magic weight loss pills when the company’s PR rep first pitched me. For some reason I decided to take a shot though, and I’m glad I did.

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Smart + Buttons (pronounced “smart buttons,” without the plus) looks about the same as any other screen protector out there, but it packs a fantastic feature that other similar products do not: It adds two invisible buttons to your iPhone.

According to PureGear, the Smart + Buttons case uses “special circuit transmitters” to add two new touch contact points to your iPhone. A touch to the bottom-left corner beneath the screen is registered by the iPhone as a tap in the top-left corner, and a touch to the bottom-right corner is registered as a tap in the top-right corner. As a result, the Smart + Buttons screen protector effectively adds a back button underneath your iPhone’s display in the bottom left corner, since anytime a “back” function appears in the iPhone’s user interface, it appears in the top-left corner.

Here’s a video from PureGear that shows the Smart + Buttons screen protector in action:

I’ve spent some time testing Smart + Buttons on an iPhone 6 and an iPhone 6s, and it works. In fact, it works very well. As noted in the video, you do have to press the touch targets with the pad of your finger in order for button presses to work, but they worked very consistently for me. Also of note, this screen protector didn’t interfere at all with 3D Touch on my iPhone 6s.

The only issue I noticed with Smart + Buttons is that light taps in the top corners of the screen on the area where the screen protector’s “special circuit transmitters” are linked aren’t always registered by the phone anymore. I needed to press a bit more firmly when I tapped those spots instead of using the new invisible buttons beneath the iPhone’s display.

Apple’s decision to not include a physical back button on the iPhone has never been much of a problem for people who have used iPhones for years, but I do hear from many former Android users who miss having a back button on their phone. Smart + Buttons doesn’t solve that problem since it only works on screens where the back function is available in an app, but it does make the phone feel as though it has a back button. What’s more, it makes reaching that button much easier than it has ever been, which is especially important now that Apple’s iPhone’s feature larger displays than they have in the past.

The Smart + Buttons glass screen protector costs $40 on the PureGear website, and it’s available for the iPhone 6/6s and iPhone 6 Plus/6s Plus. The iPhone 6 Plus/6s Plus version can also be purchased on Amazon with free shipping.