Schengen Calculator now supports iPhone Duo.

The iPhone Duo folds open into a much bigger inner screen. A Schengen calculator is a good fit for that extra space: most of the time you want two things at once, such as how many days you have left and the trips that used them up, or the trip you're planning and whether it fits. So instead of stretching the iPhone layout across the fold, we redesigned each screen to use both halves.

What changes when you unfold it

Open the Duo and these screens lay out one pane on each side of the hinge: Overview, Trips, Planner, Settings, Calendar, the Travel Report, the 90/180 rule explainer, onboarding and Schengen Pro. Here's what that looks like.

Overview

The days you can still stay, your next day back, when your 180-day window starts and a timeline of the last 180 days sit on the left. The trip you're on now, shortcuts to the calendar, planner and PDF export, and your recent trips sit on the right (picture at the top).

Trips and details, side by side

Your stays on one side, grouped into ongoing, upcoming and past, and the trip you tap on the other: days so far and to go, its effect on your balance, the date its days drop out of your window, and your notes. No more jumping back and forth.

Plan on one half, see the result on the other

Pick the entry and exit dates on the left; the right half shows straight away whether the trip fits, the days used on exit, the days left and the longest stay you could take.

Your calendar, opened up

The month on one side, with past, ongoing and upcoming days marked, and that month's trips and totals on the other.

A clean PDF for your visa

Choose the dates and options on the left and preview the Travel Report on the right before you export it.

The 90/180 rule, explained

The explainer reads like a book: the three steps of the rule on one side, and the points that catch people out, plus the list of Schengen countries, on the other.

The app follows the hinge as you use it. Fold it shut and you're back on the outer screen, where a trip opens as a detail page like on any iPhone.

The details we sweated

Splitting at the fold, not the middle of the screen

Our first version split the panes in the middle of the "safe area", the part of the screen iOS keeps clear of the status bar and tab rail. On the Duo that's lopsided, so the top pane ran across the crease. We now split at the physical middle of the screen, with a small gap either side of the hinge. When the Duo is held upright, we drop the date above "Overview" so the whole status card fits above the fold.

Keeping the tab bar

On iPad the app uses a sidebar. On the Duo it keeps the familiar tab bar instead, and iOS draws it as a rail down the right-hand edge. The info and + buttons move into that right-hand column too, under the status icons, as you can see in the pictures above.

Small panes inside a big screen

Some panes are shorter or narrower than a normal iPhone screen. So recent trip dates stay on one line in the narrow upright column, the Planner drops its separate Duration card, and onboarding's Skip button moves to the top when the device is upright.

For developers: how it works

The app watches the hinge with UIHingeInteraction, new in iOS 27.1. It reports whether the device has a hinge and whether it's open, and the window's shape tells us which way it's held. That becomes a single posture value that every screen reads from the SwiftUI environment:

enum DuoPosture {
    case none            // not a Duo: normal iPhone / iPad layouts
    case closed          // outer display
    case openLandscape   // panes left and right of the hinge
    case openPortrait    // panes above and below the hinge
}

Before iOS 27.1, and on devices without a hinge, the posture is .none, so every other iPhone and iPad keeps its existing layout. We tested by opening and closing the hinge on the iPhone Duo simulator in Device Hub. Because the hinge can't be opened from the command line, a debug launch option also runs the app in a frame the size of the Duo's inner display on a bigger simulator.

Get it

Update to version 1.0.3 or later from the App Store. Duo layouts need iOS 27.1 on an iPhone Duo; the app itself still runs on iOS 17 and later. Everything else in the app is the same: your trips stay on your device, and alerts, the planner and PDF reports are free. See everything the iPhone app does.