For apps on Apple's foldable iPhone
iPhone Duo app development: update, rebuild or build new
Your app runs on iPhone Duo, but unless it is built for it, it opens as a small window in the middle of the screen. We check it free, then design, build, test and resubmit it at a fixed price.
From ₹80,000 in India, £2,500 in the UK and US$3,000 elsewhere, fixed in writing before work starts.
What changes on iPhone Duo
The SDK your app was last built with decides what people see
Apple's guidance sets out three cases. Most apps in the App Store today are in the first.
- iOS 26 SDK or earlier
- Runs, but opens in the middle of the inner display with empty space around it.
- iOS 27 SDK
- Fills most of the inner display and keeps clear of the status bar on the right edge.
- iOS 27.1 SDK or later
- Uses the full display, with toolbars and tab bars running vertically. Screens have to be adapted first.
Fixed-price starting points
What iPhone Duo work costs
Your final price is fixed in writing after a free call, and doesn't change unless you change the plan.
| Work | India | UK | US and elsewhere |
|---|---|---|---|
| Update an existing appMove to the iOS 27.1 SDK, fix layouts for both displays and every pose, test, new screenshots, Apple's review | From ₹80,000 | From £2,500 | From US$3,000 |
| Rebuild an app that can't be savedA modern app that keeps your brand, data and users, when the old code isn't worth fixing | From ₹2,50,000 | From £4,000 | From US$4,500 |
| New app, Duo-ready from day oneDesigned for both displays and every pose, for iPhone or iPhone and Android | From ₹3,00,000 | From £8,000 | From US$10,000 |
Every price includes design, build, testing in Apple's iPhone Duo simulator, new App Store screenshots and the review. Apple's own fees are separate. In detail, by country:India,UK,US and other countries.
How it works
Everything handled, from the check to the App Store
Free iPhone Duo check
Send your App Store link. Within two working days we email what it most likely needs and what that costs.
A free 30-minute call
We go through the findings and your plans for the app.
Plan and fixed price
Scope, timeline and price in writing within 5 to 7 business days.
Design in Figma first
Each key screen on the outer display, the inner display and half-folded, approved by you.
Progress every week
A short update every week and a TestFlight build to try every two weeks.
Tested in every pose
Xcode's iPhone Duo simulator for every pose, plus your team's own iPhones.
Screenshots and review
New iPhone Duo screenshots designed, uploaded and taken through Apple's review.
After launch
Fixes, App Store optimisation, SEO and ads, if you want the customers handled too.
Free iPhone Duo check
Get a free iPhone Duo check for your app
Send us your app's App Store link. Arjun will check when it was last built, whether it carries the iPhone Duo badge and how its screens are laid out, then email you what it most likely needs (an update, a rebuild or nothing yet) and what that would cost in your currency, within two working days. It's free, with no obligation.
Apps we have built
We have shipped big apps end to end
We designed and built Bharosa, a mental-health platform with a patient app, a doctor app and a care portal: more than 350 screens, with the patient app on the App Store and Google Play in 10 weeks. For Build-Hive, a UK construction SaaS, we built the core platform in 12 weeks.
Guides
Read before you decide
- Why does my app look small on iPhone Duo? (And how to fix it)
- iOS 27 and iPhone Duo: what every app owner needs to update
- iPhone Duo App Store screenshots: sizes and the April 2027 deadline
- iPhone Duo app development in India: update, rebuild or build new (2026 costs in ₹)
- iPhone Duo app development in the UK: update, rebuild or build new (2026 costs in £)
- iPhone Duo app development in the US: update, rebuild or build new (2026 costs in US$)
FAQ
Questions about iPhone Duo apps
Will my app stop working on iPhone Duo?
No. Apple says apps built with the iOS 26 SDK or earlier still run on iPhone Duo. When the phone is open, the app sits in the middle of the inner display with empty space around it. It works, but it looks unfinished on a phone that costs ₹2,99,900, £1,999 or $1,999.
Do I have to update before April 2027?
Apple says iPhone Duo screenshots become required from April 2027. Updating before then means your app looks right on the phone now and is ready for that change, instead of being rushed through it.
Can you update an app another developer built?
Yes, if you can give us the source code and access to your Apple developer account. If the code turns out to be beyond sensible repair, the plan says so and prices a rebuild instead.
Do you test on a real iPhone Duo?
We test every pose in Apple's iPhone Duo simulator in Xcode 27.1, which Apple calls the best way to test the full experience, and send TestFlight builds to your team's own iPhones every two weeks.
Do you handle Android foldables too?
Yes. If your customers also use Android foldables, we plan layouts that adapt on both platforms: native Android in Kotlin, or one cross-platform app in Flutter, chosen per project.
Will I own the code and the App Store account?
Yes. The code, the designs, your Apple developer account and App Store Connect stay in your name from the start.
Free 30-minute call
Tell us about your app.
You get a short plan back: what your app needs for iPhone Duo, how long it takes and what it costs, in your currency.