Getting the most out of apps on iPhone Duo
iPhone Duo is Apple's first foldable: a 5.4-inch outer display and a 7.6-inch inner display that opens like a small book. The hardware is impressive, but the experience depends on whether each app has been updated for it.
Optimized vs. unoptimized apps
Apps built with Apple's newer SDK can adapt their layout as the device folds, unfolds and rotates. Apps that haven't been updated still run, but on the inner display they appear with black bars or empty space instead of filling the screen. Optimized apps carry a “Made for iPhone Duo” badge on the App Store. Every app in our directory has been announced or confirmed as optimized.
Four ways apps use the fold
1. Big screen
The simplest win: the app uses the full inner display with a richer layout, typically an iPad-style sidebar plus content. Mail clients, calendars and note apps benefit most. You stop drilling in and backing out of screens.
2. Split View
Side-by-side multitasking, previously limited to iPad, comes to iPhone on the Duo. Pair a document with a reference, or a chat with a map. Apps that support it resize cleanly when they share the screen.
3. Tabletop (half-folded)
Set the Duo on a surface half-open, like a tiny laptop. The best apps split their interface along the hinge: video on top, controls or stats below. Recipes, live sports, video calls and flight tracking are natural fits.
4. Cover screen
Closed, the Duo is a compact phone. Some apps offer a deliberately different experience on the outer display — quick browsing, pick-up-and-play gaming — then carry on where you left off when you open it.
Tips
- Check for updates first. Many developers shipped Duo support in an update. If an app shows black bars, update it before giving up on it.
- Try tabletop for anything you watch. Propping it half-open frees your hands and often reveals a layout you'd never find otherwise.
- Use StandBy on either screen. StandBy works on both displays, even when the phone isn't charging.
- Games adapt controls. Titles like Zenless Zone Zero rearrange touch controls depending on how you hold the device, so try each position.