Apple says that developers have been rapidly adapting their apps for the iPhone Duo's twin screens, with thousands of new ones being added daily.

The lack of apps that hadn't been updated for the iPhone Duo was definitely the device's Achilles' heel. But as AppleInsider said, that problem was small, getting smaller, and by the time most buyers get their iPhone Duo, it will be gone.

Now in a statement to AppleInsider, Apple has boasted about the rate at which developers are updating to take advantage of the iPhone Duo.

"It's been wonderful to see how quickly developers have embraced iPhone Duo, and we're grateful for their creativity and innovation," Susan Prescott, Apple's vice president of Worldwide Developer Relations. "Today there are well over 100,000 apps built for iPhone Duo already live on the App Store, and thousands of optimized apps are being added to the store each day."

Prescott made similar remarks in late October 2026, but since then has added more detail about how Apple is working with developers.

"In the last month alone, thousands of developers have joined us for workshops in 19 cities around the world to experience iPhone Duo firsthand and bring updated apps to their users," she said. "The enthusiasm has been incredible, and we're excited to see the pace of updates continue to accelerate as more and more apps optimize for iPhone Duo."

Separately, a particularly notable update for the iPhone Duo has been from Google. Larger firms such as Google and Microsoft have often been very late to adopting new Apple requirements, but Google has rapidly updated its Maps app.

Why apps need updating

If developers have consistently followed Apple's recommendations, then their apps already make some use of the iPhone Duo's two screens. But to fully use the width of both the external and internal screens, developers need to do some work.

Two foldable smartphones on a table, both opened and displaying a satellite map of a dense city with buildings, streets, and location markers.

How the updated Google Maps uses the whole of the inner and outer displays on the iPhone Duo.

Apple says that this extra work is minor. But if developers have not been following those recommendations, then the effort needed is much more substantial.

It's also much more important, too. Such apps are shown in the center of the inner screen with large black bars to left and right.

Users can expand the app to more or less fill the screen, but it looks poor. Plus users can drag such an app to one side of the screen or the other, and then open a second app to fill up the rest of the screen.

But then beyond their appearance, apps that have been properly updated for the iPhone Duo make extra use of the device's form factor. Apps can tell how wide open the device is, for instance, and adjust their controls to best serve the user.