Test your app on iPhone Duo in the Simulator

What you need

• Xcode 27.1. Apple says it "adds development support for iPhone Duo". Xcode 27.0 shipped without it.
• macOS 26.6 or later. That is the minimum Xcode 27.1 declares in its Info.plist.
• The iOS 27.1 simulator runtime. The iPhone Duo device comes with it.

Check what you have with these two commands:

xcodebuild -version
xcrun simctl list devices available | grep "iPhone Duo"

If the second command prints nothing, add the runtime. It downloaded with no Apple ID on our Macs:

xcodebuild -downloadPlatform iOS

Boot the iPhone Duo simulator

After the runtime installs, a device named iPhone Duo is already there. You do not have to create it. Boot it and open the Simulator window:

xcrun simctl boot "iPhone Duo"
open -a Simulator
xcrun simctl install booted MyApp.app
xcrun simctl launch booted com.example.myapp

Apple points developers to Device Hub to see the app in every pose and orientation. Device Hub ships inside Xcode 27.1, at Xcode.app/Contents/Applications/DeviceHub.app.

Run your tests on iPhone Duo

Use the device name as the xcodebuild destination. This is the same line you would put in CI:

xcodebuild test -scheme MyApp \
  -destination 'platform=iOS Simulator,name=iPhone Duo,OS=27.1'

On our M6 Mac mini, a small Swift package ran its tests this way in 19 seconds. That time includes booting the simulator. Your app will take longer, but the setup is the same.

App Store screenshots

Apple says that starting April 2027, every app or game submitted will need iPhone Duo screenshots. Apps that submit them now get a badge on the App Store page. You can take one from the booted simulator:

xcrun simctl io booted screenshot duo.png

Ours came out at 1398 by 2034 pixels in the default pose. Check it against the current specifications in App Store Connect before you upload.

Where to run it

If you have a Mac on macOS 26.6 or later, install Xcode 27.1 and you are done. If you do not, or your Mac is too old, a rented Mac works. Every free MacRun Mac now has Xcode 27.1 and the iPhone Duo simulator set up before you log in. Xcode 26.6 is installed too. A day pass is $15 and a week is $59. You see the screen from any computer, including Windows.

What the simulator cannot tell you

• It is not the real phone. Speed, memory and touch feel differ.
• Some hardware, such as the camera, is missing or simulated.
• Test on a real iPhone Duo through TestFlight once you have one.