Apple makes it sound easy to update apps for the new iPhone Duo. It's going to take some developers longer, not everything will work well at first, and some won't do it at all.
Even though everyone believed a foldable iPhone was coming, Apple did manage to keep the iPhone Duo secret better than usual. Which means that as well as surprising buyers, it can have startled most developers.
Not all, of course, as Apple reached out to ones such as Netflix in order to have third-party apps to show at the launch. Then, too, when Apple insists that updating apps to work on the new device is straightforward, it means if developers have already been following its guidelines.
Apple will often recommend that developers do things in certain ways, but it practically never says why. So faced with investing time and money in either new features or just updating old ones to fit new guidelines, developers may well opt for the former.
They're fine to do that until such time as Apple brings out a new device. Then suddenly they have a lot of work to do, and in this case they don't have long in which to do it.
It's not that their app won't work on the iPhone Duo, it's that it will look poor. There is also the fact that it won't take advantage of any new features, but the primary issue is that their app may look dreadful until it's updated.
Don't presume that it's the small, one-man-band kind of developer who is now facing this. Firms such as Microsoft and Adobe are famously slow to adapt, because they're working to their own schedules rather than Apple's.
Ultimately, apps will have to support all of these different layouts on the iPhone Duo - image credit: Apple.
So for any favorite app you have, if you get an iPhone Duo on the day it first ships, there are three possibilities:
- The app will look dreadful
- The app will look good to okay
- The app will work perfectly
It's going to be pretty rare for an app to work perfectly, looking right and using all of the new features, on day one. It's much more likely that apps will be in that middle ground.
If they are, it's because the developer has already been following Apple's guidelines and made apps that are adaptable to different screen sizes. That isn't the same as being able to adapt perfectly to the iPhone Duo, however.
That's because developers have been able to see how their apps look, either in reality on an actual iPhone Duo, or in the Xcode tool's app preview. Xcode only added that iPhone Duo preview with version 27.1, which was not released until after the launch presentation.
More to it than display size
The obvious way that you will see how much apps have or haven't been updated is in how they are shown on screen. Ones that haven't been touched will display in the center of that opened out inner screen, with huge black bars left and right.
Ones that have been made following Apple's guidelines will look much better but be ever so slightly shy of filling up the whole screen. They also may not have features such as moving their controls depending on how open you have the iPhone Duo.
There are also so many more specific questions developers have that Apple held an hour-long iPhone Duo Group Lab session.
For the most part, the answers given boiled back down to how if developers follow Apple's guidelines, their apps will work. That's partially true, but there are more orientations, screen sizes, and so forth to incorporate that developers had no idea about before. There are also new APIs that are brand new, literally days old.
But there were ones that even Apple's panel wasn't yet sure about, such as whether apps can detect which way up a device is. And then there were ones such as a question about the front screen and what can run on that.
When the iPhone Duo is closed, that front screen is a regular iPhone, if slightly more squat. Once the iPhone Duo is opened, the front screen turns off, except in certain circumstances.
Developers want to know if they can use the iPhone Duo's front screen even when the device is open.
The only ones shown in the announcement were when a FaceTime call uses both front and open screens, and when the camera uses Kid Cue to display an animation of Snoopy to get your child to look toward the lens.
What developers want to know is whether they can use that front screen alongside the inner one for features such as a teleprompter display. There Apple was more specific, promising that if the app was using the camera, it could control the front screen.
Developers want to do this
All that really means, though, is that Apple has enabled that and other features, providing an API to let developers use them. It still requires those developers to think through what they need and what suits their app, before they even start coding.
Plus the iPhone Duo is launching only about six weeks or so after the release of iOS 27. Every year, every developer has to devote some time and resources to making sure their app works properly with the new iOS.
They have had months since WWDC's reveal of iOS 27, and they have had multiple beta test versions to try out. But there are some old hands at this who know not to bother updating their apps until the new iOS is actually out because Apple keeps changing things through the beta cycle.
Consequently, any developer who sat out the betas had good reason, there was precedent for not wasting time on fixes that would later have to be redone. But they now have to work on that as well as preparing their app for all that the iPhone Duo brings them.
It's hard to even guess what proportion of apps will be right or nearly right when the iPhone Duo launches. Unless the developer is solo, or a small team, they will be working on this and working on it as quickly as they can.
Microsoft and Adobe are not historical early adopters, so don't expect it from them early either.
