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 ho.