Best apps for the iPhone Duo's outer screen

The outer display is the screen you see with the iPhone Duo closed. Each pick below has documented closed-phone behavior, a price and a catch. Prices are US, as of Nov 6, 2026.

How apps behave on the outer display

Apple says both displays share an aspect ratio, so apps scale from the outer display to the inner one and users can pick up where they left off, per its October newsroom post on Duo apps. Apple's design guidance moves buttons and navigation bars to the side on the outer screen to leave more vertical room, iClarified reports.

Apple's developer page for iPhone Duo says apps built with the iOS 26 SDK show their content to the left of the status bar and camera when the Duo is closed, while apps built with the iOS 27.1 SDK or later use the full display.

9to5Mac reports that Safari's right-side controls take up a significant portion of the outer display's limited space, and that websites can't currently extend behind them. WebKit's Jen Simmons says Apple is exploring ways to let websites make better use of the outer display.

Left-handed? TapSmart reports that you can't move the Dock or app controls to the left side of the outer display.

Built-in features that work closed

Camera

Apple says you can take a selfie with the higher-resolution rear cameras and preview the shot on the outer display, per its iPhone Duo announcement. Duo Preview and Kid Cue use the outer display too (see iPhone Duo tips). These built-in features come with the phone, with no app to buy. The limitation: John Gruber reported, in his Daring Fireball review, accidental photos from pressing Camera Control while opening or closing the Duo.

FaceTime

Apple says Duo FaceTime lets people who are with you join a video call on the outer display. To turn it on, unfold the Duo, start a Group FaceTime video call, tap the screen, tap More and then Duo FaceTime, per MacRumors' FaceTime how-to. The limitation: you start it from the unfolded phone.

StandBy and Live Activities

Apple says the Duo enters StandBy on either display when you set it down, and the Dynamic Island now sits vertically on the side and expands for Live Activities and alerts. TapSmart adds that the Dynamic Island grows downward as Live Activities arrive. The limitation: Gruber saw a Live Activity, with the keyboard up, squeeze an app's toolbar on the outer display, folding its Done and Close buttons into a menu.

Touch ID and Apple Pay

Apple says Touch ID in the side button handles authentication whether the Duo is open or closed, and its Touch ID support document covers using Touch ID with Apple Pay. The limitation: there's no Face ID, as Consumer Reports points out. More on setup: how to set up Touch ID properly.

Messages and quick lookups

Consumer Reports found the outer display best suited to quick tasks like sending a text, checking email and looking something up online. The limitation: Gruber found that with the keyboard up, the outer display leaves very little room for earlier messages, though he says rotating the device shows more and makes thumb-typing easier.

Third-party apps that work with the Duo closed

RainViewer

MeteoLab's RainViewer 8.4 release notes say everything moves to the outer display when the Duo is closed, with navigation adapting to every orientation, per its App Store listing. As of Nov 6, 2026, it's free, with in-app plans listed from $3.99 a month up to $39.99 a year for Pro, plus a 14-day trial for Essential and Pro. The limitation: the listing's plan names overlap and repeat, so check which tier you're buying.

Google Maps

Google Maps version 26.44.4 fills both the inner and outer screens, MacRumors reported on Nov 4, while version 26.43.1 left a black border on the right of both. Check the version in the App Store before updating. The app is free (with in-app purchases) on the App Store. The limitation: Google's release notes don't mention the Duo, and MacRumors doesn't describe navigation on the outer display.

Netflix

Apple says you can scroll through Netflix Clips on the outer display, then open the Duo to keep watching on the inner display. Netflix needs a paid plan: US plans cost $8.99 a month for Standard with ads, $19.99 for Standard and $26.99 for Premium, per Netflix's help center. The limitation: the closed view is for browsing Clips; the full setup is in best video apps.

Tiimo

Apple says the Tiimo planner has a compact view when the Duo is closed, for checking the day's plans and ticking off tasks. Tiimo is free with in-app purchases, and its App Store listing shows Pro options from $7.00 to $54.00 without naming each plan. The limitation: the latest 3.70.1 notes cover Apple Watch, not the Duo.

Deck-Man: Cassette Player

Squircle Apps' Deck-Man lets you open the Duo to pick an album and insert a tape, then close it to start listening, per its App Store listing. It costs $4.99 with no in-app purchases or subscriptions, and plays Apple Music or music files on the phone, iThinkDifferent reports. The limitation: neither source describes what the outer display shows during playback.

Sneaky Sasquatch and Retrocade

Apple says these Apple Arcade games offer quick pick-up-and-play fun when the Duo is closed. Apple Arcade costs $6.99 a month or $49.99 a year, per Apple's Arcade page. The limitation: Apple hasn't described what either game shows on the outer display.

The outer display gets longer video playback

Apple rates the Duo at up to 44 hours of video playback on the outer display versus 31 hours on the inner display, and 37 versus 26 hours for streamed video, per its spec page. More in iPhone Duo battery life and how to extend battery life.

Bottom line

For checking, replying, paying and shooting, the built-in features cover most closed-phone use, and RainViewer and Tiimo are the third-party picks with the clearest outer-display layouts on paper; Google Maps 26.44.4 fills the outer screen, per MacRumors. Long reading, typing and browsing still belong on the inner display, so see best reading apps and best apps for iPhone Duo. Left-handed buyers should weigh the fixed right-side Dock first.

Which apps do you open without unfolding?