I spent Wednesday in New York, interviewing developers about their iPhone Duo apps. It was like a little slice of WWDC dropped among Manhattan’s skyscrapers, which was wonderful. There’s nothing I enjoy about what we do at MacStories more than talking to developers about their apps and the stories behind them.I left the city with a much better appreciation for what it’s like to build apps for the Duo, which will be incredibly valuable as Federico and I work our way through the enormous list of Duo apps that developers have shared with us. I also left New York with a 512GB Night Sky iPhone Duo for testing. As I left the press event, I suddenly had a phone to set up, but hadn’t done anything to prepare and had no fast Wi-Fi to download gigabytes of apps and files. Long story short (listen to MacStories Unwind for the long version), I headed to the airport and by the time I boarded the plane, I was on the iOS 27.2 beta and had the core system apps installed.So, suffice it to say that this is not a review of the iPhone Duo. I haven’t had it much more than 24 hours, so I haven’t fully settled into a routine with it. That said, I wanted to share my first impressions and some early surprises.First, let’s talk about the hardware. I ordered myself a Star White Duo in part because my current iPhone is a 17 Pro Max in Deep Blue and I wanted something different. In photographs, the difference between Deep Blue and Night Sky struck me as minor, like shades of the same color. That’s not the case. In reality, Night Sky is a very dark blue like the name suggests. In bright sunlight, the blue of the phone is drawn out, but at other times it looks more like a deep slate slate blue that approaches black. As someone who has gone for some variation of Space Gray more often than not when buying Apple gadgets, I like it a lot.The iPhone Duo comes unfolded in the box, looking more like an iPad mini box than any past iPhone packaging. It’s a nice way to show off the most expansive screen on any iPhone, but of course, I immediately folded it in half. The Duo is striking when folded because it’s both shorter and wider than any iPhone. It’s also heavy and dense. The Duo is just five grams heavier than the iPhone 18 Pro Max, but it’s the concentration of that weight in the Duo’s small footprint that makes it feel so dense.StandBy mode.I’ve been using Apple’s largest Pro iPhones ever since they were first introduced, so I’m used to a hefty phone. However, the Duo is different. Its weight is concentrated in the palm of your hand. That gives the Duo a heft in your hand that feels substantial and premium.There’s no getting around that this is Apple’s heaviest iPhone, but the size makes gripping the Duo easy in a way that a Pro Max model isn’t. I also suspect the Duo will be easier to hold one handed for longer because there’s very little of the device that hangs outside the bounds of your hand. However, whether that’s a perceptual trick or real will require longer-term use.The iPhone Duo is also Apple’s thinnest iPhone ever when it’s unfolded. However, folded, it’s a chunky boy that feels very different to hold than past iPhones. That may turn some people off at first, but I like it myself. We’ve tested many, many videogame handhelds of all shapes and sizes for NPC: Next Portable Console, and I’m here to tell you that small devices can be too thin to be comfortable to hold for long periods. Now, I’m not suggesting that the Duo is the perfect folded thickness – just that when used closed, that thickness makes it easier to get a grip on the device.Music on the Duo.The Duo’s reliance on Touch ID is a mixed bag. It’s not as convenient as Face ID, but for unlocking the Duo, I haven’t missed Face ID much. The times I feel the lack of Face ID is when I’m logging into websites or apps, which is something that you wind up doing a lot when you have a new iPhone. The Duo’s Touch ID is fast and the button’s placement works well whether you hold the device in your left or right hand, but there’s no getting around that simply looking at your iPhone’s screen is better.The most remarkable part of the iPhone Duo’s hardware is the one that there’s the least to say about: the hinge. It works at any angle without slamming open or shut, but closes with a satisfying thunk as the two halves meet and stick to each other with magnets. The outside of the hinge is protected by a cover, and the crease where the inner screen closes is barely noticeable thanks in part to the screen’s nano-texture covering.That layer, which is replaceable, gives the inner screen a smoother, warmer feel than naked glass does. When you use a USB-C Apple Pencil (currently available in the iOS 27.2 beta) with the Duo, the nano-texture layer makes it feel like writing on paper as well as or better than any third-party “paper-like” film I’ve tried.The nano-texture layer also cuts down on glare, which makes the Duo a delight for reading. The other nano-texture display I’m most familiar with is the MacBook Pro’s, which I think does a better job reducing glare, but for reading and other tasks under bright lights or sitting outside, the Duo gets the job done, too.Tent mode. Nice.What’s not as great about the Duo’s hardware is that it’s easy to accidentally hit the side buttons when opening and closing the device because they cover a fair amount of the edges. It’s also easy to lose track of where the buttons are when the Duo is unfolded because it can be used in any orientation that way. Another oddity that there’s no getting around is that it’s a little strange that the buttons aren’t centered on the sides when the Duo is folded because they can’t be. The same goes for the USB-C port, which has made me a little paranoid about accidentally jamming a USB-C cable between the Duo’s two folded halves, scratching the inner screen.Those sorts of unique characteristics are in abundance on the Duo and not just when it comes to the hardware. It’s true of iOS on the Duo, too. Apple has moved many controls, including the Dock itself, to the edges of the screen. That’s a design reachability win when the Duo’s screen is unfolded, but it means relearning years of UI interactions that are second nature to iPhone users.I happen to love that sort of change. That doesn’t mean I think Apple nailed the design in every instance, but it’s exciting to try a device that allows Apple to break with conventions and try new interaction models. Not everyone is like that, but if you know, you know.It’s also worth noting that the iPhone Duo is called an iPhone for a reason. It’s not an iPad and the software choices reflect that. In some cases, that’s a bummer. I’d love pointer support beyond what’s available as part of the Assistive Touch Accessibility settings. I’d also like the ability to move the Split View divider horizontally to give one app more room on occasion, but that’s not possible. Split View is strictly a 50/50 affair. I’d also like to use Command + Tab to switch between apps when the Duo is paired with a keyboard, which isn’t possible either. However, with a screen smaller than even an iPad mini, I don’t think it’s realistic to expect Apple to ever do multi-windowing or splits of the short side of the screen.A lot has been made of the state of apps optimized for the iPhone Duo. If an app isn’t optimized and you’re using the Duo unfolded in landscape mode, the app can appear in the center of the screen with big black bars on the side, shifted off to the left side of the screen, or shifted to the right side. In this orientation, the smart bet is to pair the unoptimized app with another app in Split View where the difference mostly fades away. Also, if you’re using an unoptimized app in portrait mode, you can supersize it with a zoom button reminiscent of the iPad’s “2x” button for iPhone apps. It doesn’t look great, but the screen is better utilized that way.MacStories readers tend to use more apps than most people, so you’ll probably run into unoptimized apps and be a little annoyed. But I also expect you’ll be pleasantly surprised by how many apps are already optimized for the Duo. We’ve been contacted by hundreds of developers who have updated their apps for the Duo, and it’s not just limited to indie developers. Bigger players, like some of the folks I interviewed in New York, have updated for the Duo, too.So, while I agree that using an unoptimized app on a Duo isn’t a great experience, I don’t think the state of app updates is a reason to avoid the Duo. You will undoubtedly have a few favorites that will take a little longer to update, which is what makes this seem like a bigger issue than it is. However, if you step back and look at the App Store more generally, the update narrative is a MacGuffin that I’m sure will resolve itself quickly.iPhone 17 Pro Max (left) and iPhone Duo (right)Before diving into some miscellany, I wanted to offer a few side-by-side photo comparisons using my iPhone 17 Pro Max and the iPhone Duo. These images were taken on a sunny afternoon and haven’t been processed.I haven’t taken many photos with the Duo yet, and no video, but so far, I’m pleased with the results. What I felt more was the lack of a 4x zoom option. I’m looking forward to testing the Duo in more challenging settings like at night, to see how the camera compares to the Pro phones I’ve been using for years, but the early results are encouraging.To wrap things up, I want to present my “First 24 Awards” for some of the best and worst things I’ve discovered about the Duo in the past day. Here we go:Most Surprising Accessory: When I first saw the iPhone Duo Folio with Kickstand I was left scratching my head and grimacing at the $129 price. But after just one day, I love it. The case attaches magnetically and has a flexible cloth section that wraps around the Duo’s hinge like the spine of a book. In fact, the whole package looks and feels like a premium notebook. The cover protects the Duo’s outer screen but flips back when using the outer screen and is easily held out to the side when taking photos.iPhone Duo Folio with Kickstand.A look at the iPhone Duo Folio’s kickstand.The folio case’s hinge, which you can see tucked up underneath the kickstand when it’s unfolded, is stiff and feels sturdy. While I was testing the Duo I took it out on my balcony, unfolded it, and propped it up with the kickstand to take notes for this story in Obsidian, and it was a great way to write. Overall, the iPhone Duo Folio with Kickstand gets two enthusiastic thumbs up from me.Biggest Accessory Bummer: I have a NOMAD MagSafe-compatible wallet that incorporates Find My features. Aside from being able to more easily locate my wallet when I misplace it, I love that it holds one more card than Apple’s wallet does. Unfortunately, it hangs off the end of the iPhone Duo, so that’s not going to work. According to 9to5Mac’s Chance Miller, Apple’s MagSafe wallet has the same problem. And, even if it did work, I think the added thickness would probably be a nonstarter, so it looks like I’ll be shopping for a new wallet soon.Logitech Keys-to-Go 2 with the Duo and Apple Pencil USB-C.Best Third-Party Accessory: I plan to write more about iPhone Duo accessories soon, but if I had to pick just one third-party accessory to go with the iPhone Duo Folio with Kickstand it would be Logitech’s Keys-to-Go 2 keyboard, which I like because the keys are full or near-full sized, it’s super slim, it has a cover to protect the keys, and it can run for months on watch batteries.Reading in Books.Best Apps For Unfolded Mode: It’s not surprising, but any app that benefits from a bigger screen is excellent on the Duo, including apps like Apple Books, almost any email app, Notion, Slack, and Jump Desktop and other apps for remotely controlling a Mac. I’m sure there are many more, but after just 24 hours, I still have a lot of apps to try.Best Hidden Feature: Shortcuts has an action that can be used to trigger automations based on whether the iPhone Duo is open or shut. I haven’t spent a lot of time thinking about how I might use that action yet, but I’m sure you’ll hear more about it from Federico or me soon.Biggest Productivity Win: I wouldn’t be surprised if two side-by-side apps is the most popular iPad configuration for getting work done. I know that’s my favorite setup, which is why I was so glad to see it on the iPhone Duo, too. Once you set up a pair, you can lock the apps together with a tap of the divider between them, so you don’t have to set it up from scratch every time. I expect I’ll use app pairs a lot and perhaps write about my favorite pairs after I have a chance to settle into a routine with the iPhone Duo.I hope that gives everyone some things to think about and try when their iPhone Duos arrive today and helps others decide whether it’s for them. As always, if you have questions about this story or the Duo in general, get in touch on social media or in the Club MacStories Discord, and I’ll see what I can do to find you answers.