How many apps does the iPhone Duo have?
Apple said on 6 November 2026 that more than 100,000 apps are now built for the iPhone Duo. The company shared the figure with TechCrunch, CNET and MacRumors, two weeks after the foldable went on sale.
The Duo became available on 23 October, according to Apple's developer news. It starts at $1,999 for the 256GB model, TechCrunch reported, making it Apple's most expensive phone.
Apple says thousands of optimized apps are being added to the App Store each day. That pace matters because the device depends on third-party software to justify its larger inner screen.
The 100,000 figure is large for a form factor that is two weeks old. It is also smaller than it sounds. The App Store carries millions of apps, and Apple counts any app built with a recent software development kit.
The visible signal for shoppers is a Made for iPhone Duo badge on App Store product pages. Apple's statement described the apps as optimized, but the badge is the part buyers can actually check.
Apple is also late to the category. Samsung, Google and Huawei have sold folding phones for years, and their developers have had more time to adapt. Apple is entering with a new screen shape and its existing iPhone customer base.
The Duo comes in four storage tiers: 256GB, 512GB, 1TB and 2TB, according to Apple's specifications.
Apple's launch pitch leaned on entertainment and productivity. Netflix, Prime Video, Paramount+, MLB and the PGA Tour were among the first apps to use the wider canvas. Those apps show what the screen can do when a developer commits to it.
What counts as an iPhone Duo-optimized app?
MacRumors confirmed that the 100,000 figure refers to apps built with the iOS 27.1 SDK or later. These apps fill the full width of both displays and move vertical controls into the status bar.
Apple draws a second, lower line. Apps built with the iOS 27 SDK resize to fill most of the inner display. They avoid the status bar on the right edge.
Apps built with the iOS 26 SDK or earlier still run. They sit in the center of the inner screen, with black space on both sides.
The difference is visible on the cover display too. An app without an update leaves a black bar along the right side, according to The Verge.
Apple's badge is tied to App Store screenshots. Developers submit Duo screenshots in App Store Connect, and the product page then shows the badge, Apple's developer guidance says.
Apple will make part of this mandatory. Starting in April 2027, every app or game submitted to the App Store must include Duo screenshots, Apple says.
That deadline raises the floor without guaranteeing a tailored layout. An app can fill the display, carry the badge and still feel like a phone app stretched across a tablet-sized canvas.
The SDK line matters because iOS 27.1 is the version that added Duo development support. Xcode 27.1 includes Device Hub previews for every pose and orientation.
A developer can meet the SDK bar without changing much. Standard SwiftUI and UIKit controls adapt automatically, which is why the count can rise quickly.
The harder work is custom. Apps with dense toolbars, sidebars or video players must decide where controls go. The screen is wider and shorter than a normal phone.
Apple's guidance also covers design templates and screenshot specifications. Those assets affect how an app looks in the store, not how it behaves after installation.
Why the app gap mattered at launch
Apple made the Duo landscape-first. The inner screen is 7.6 inches diagonally. The outer screen is 5.4 inches. Apple says the inner display is 50 percent larger than the iPhone 18 Pro Max.
The device weighs 254 grams and uses Touch ID instead of Face ID. It runs on Apple's A20 Pro chip. Both displays share the same aspect ratio, so apps scale proportionally when the phone opens.
Most iPhone apps are built for tall, narrow screens. The Duo gives them more width but little extra height. Apps that have not been redesigned can look stranded.
The Verge's review called the Duo 'one of Apple's messiest first-generation products in a long time.' It praised the matte inner display and the hardware concept. It also said the cover screen is too small for modern apps.
The review compared using the outer screen to 'having an iPhone 5 in a world of iPhone Pro Maxes.' That is a usability criticism, not a benchmark.
CNET found the same problem with Discord. The app opened in the center of the inner screen with black space on both sides. CNET noted that Android foldables went through a similar adjustment period.
Hardware durability looks stronger than the software story. CNET's review unit passed 300,000 folds in its test. The publication also praised the Duo's iOS 27 integration across both displays.
The Duo does not turn into an iPad. Apple built a new multitasking model for the phone, and some familiar iPad features are missing. The Verge noted that the Duo does not support pinching the keyboard to shrink it for one-handed use.
Split View works in landscape. In portrait, users have fewer ways to run two apps at once, according to The Verge.
Those limits matter for the apps that are supposed to justify the inner screen. A spreadsheet, an inbox or a video call can use the extra width, but only if the app places its controls sensibly.
The outer screen is the bigger compromise. Apple says it covers 90 percent of the area of an iPhone 18 Pro, but the shape is short and wide. A keyboard can leave room for only a few lines of messages, The Verge found.
Which major apps are still missing?
MacRumors published a list of notable apps that were still not optimized on 6 November. The list included several daily-use categories.
Payments and retail: PayPal, Venmo, Best Buy, Nike, Starbucks and Whole Foods.
Food and local: DoorDash, Uber Eats and GrubHub.
Travel and logistics: Delta, Southwest, JetBlue, FedEx, UPS, USPS and the MTA.
Work and Google apps: Google Docs, Google Sheets, Google Slides, Google Home, Microsoft Teams and Microsoft Authenticator.
Media and social: AMC Theaters, Amazon Fire TV, Fandango, Spectrum TV, Bluesky and YouTube Music.
Other apps: Steam, Duolingo, Goodreads, Libby, PictureThis, Ring, Verizon, Wells Fargo and the Apple Store app.
The list is a snapshot, not a verdict. Apple says updates are arriving daily. TechCrunch reported that more than a dozen notable apps had just been updated.
Those updates include Microsoft Word, Outlook, Zoom, the NBA and NHL apps, Etsy, LTK, Goodnotes, Extra and Halide Mark III. They join Netflix, YouTube, Instagram and WhatsApp, which were ready earlier.
The missing apps are weighted toward services that already have large iPhone audiences. Those teams have the most code to test and the most revenue at stake.
Some categories have a clearer payoff. Video apps can fill the inner screen with a 16:9 player and use the remaining space for controls or recommendations. Payments and messaging apps gain less from extra width.
Apple's own Store app is on the missing list, along with Best Buy. Both are retail apps with large iPhone audiences, and neither appeared optimized on that list.
Apple's newsroom also highlighted Prime Video, Paramount+, MLB and PGA Tour apps that use the wider inner display for video, stats and controls. In the MLB app, a live game can play on the upright half while stats fill the half resting on a table.
Apple's own count includes apps whose updates have not fully reached users. TechCrunch noted that Spotify still showed a black bar on its review unit. The App Store did not yet offer an update, even though Apple listed Spotify as optimized.
How Apple is courting developers
Apple has been running an intensive developer campaign for a phone that launched two weeks ago. The company hosted more than 50 in-person workshops in 19 cities. TechCrunch reported that more than 2,000 developers attended.
The workshops are part of a broader push. Apple wants developers to see the hardware, test their apps in person and leave with a build that fills the display.
The company has also published design guidance and App Store assets for the new screen. Those resources lower the cost of a basic update.
Apple says standard SwiftUI and UIKit components adapt automatically to the Duo's displays. Controls move to the status bar. The inner screen supports multi-column layouts. New APIs let developers handle different poses and multitasking states.
The company is also using the App Store as a lever. New editorial collections for Duo apps and games went live around launch. Optimized apps get a badge that shoppers can see.
Apple's developer guidance says the badge is tied to Duo screenshots. That makes store presentation part of the optimization work, not just the app's internal layout.
Susan Prescott is Apple's vice president of Worldwide Developer Relations. She said there are 'well over 100,000 apps built for iPhone Duo already live on the App Store.' She added that 'thousands of optimized apps are being added to the store each day.'
Apple cannot mandate a good layout, though. The April 2027 screenshot rule will push more developers to submit Duo assets. It does not require them to redesign navigation or split-screen behavior.
Developers still decide where to spend engineering time. A new form factor with a $1,999 entry price and constrained supply may reach fewer users than the standard iPhone at first. The 100,000 figure suggests that many developers expect the installed base to grow.
The economics are less clear. A Duo-specific layout is extra work for a device that is supply-constrained. Some teams may wait for the installed base to grow before they invest in custom navigation and split-screen behavior.
Apple's counterargument is reach. The iPhone installed base is enormous, and the Duo gives Apple another reason to sell apps and services. The 100,000 figure is a bet that the device will matter beyond early adopters.
What do early sales say about demand?
Demand has not been the problem. Apple's website sold out within hours of the Duo going on sale, according to the Financial Times, as cited by TechCrunch. Customers who did not preorder or visit a store saw shipping times stretch into next year.
Apple COO Sabih Khan said the Duo is 'constrained as of today.' He also said it is 'really hard to predict when supply and demand will be in balance.'
Khan said the ramp is going well and that Apple is working to get the device to customers quickly. Apple is also deepening its partnership with Perryman, a titanium supplier for the Duo, according to TechCrunch.
Verizon has apologized to customers for delays with gift cards, TechCrunch reported. That is a sign of how far the shortage has spread beyond Apple's own store.
The launch fell after Apple's fiscal fourth quarter closed on 26 September. The company's latest results therefore do not include Duo sales. Apple reported $114.5 billion in quarterly revenue, and BBC News reported that iPhone revenue rose 17 percent to $57 billion.
The quarter shows the scale of the business the Duo is joining. iPhone revenue reached a September quarter record, and Services set an all-time high, according to the company's results.
Memory costs are another pressure. Apple's chief executive, John Ternus, called the rise in memory prices 'unprecedented,' according to BBC News. The company said component constraints could continue into next year for iPads and Macs.
The company also faces cost pressure. BBC News reported that Apple has lifted prices on nearly all of its hardware by around 20 percent. Those increases affect the entire lineup, including the $1,999 Duo.
The screen-crack reports add a quality question. BBC News reported that some buyers found cracks along the inside fold. Apple said it would replace affected handsets, but the company did not discuss the issue on its earnings call.
What to watch next
The next test is the holiday quarter. Apple has not said when Duo supply will catch up.
The first signal will be shipping estimates. If they shorten before December, Apple has caught up. If they stay in next year, supply will remain the binding constraint.
The second signal is the quality of updates. A badge is easy to earn. A layout that makes a spreadsheet, a chat thread or a video call feel natural on a short, wide screen is harder.
The third signal is competition. Samsung and Google could respond with wider foldables and better app support. That would leave Apple less room to charge a premium for the form factor.
The April 2027 screenshot deadline is the next structural change for developers. It will push more apps to submit Duo assets. Shoppers should watch for real layout changes rather than badges alone.
Several big categories remain open. PayPal and Venmo cover payments. Uber Eats and DoorDash cover delivery. Google Docs, Sheets and Slides cover office work. Updates from any of those teams would matter more to daily use than another batch of games.
Apple is also adding features that could broaden the Duo's appeal. MacRumors reported that iOS 27.2 adds Apple Pencil (USB-C) support. That turns the inner screen into a drawing and note-taking surface.
The 100,000 figure answers the first question buyers ask: will my apps work? The harder question is whether everyday apps will feel designed for this screen. The inner screen is wider than it is tall.