iPhone Duo's Split View lets users run two apps side by side and save the pairing

The moment that decides whether an app looks finished on this phone lasts about a second. Someone has it open on the cover screen and unfolds the handset. iOS 27 fades and blurs the cover content, brings it back up on the inner display ^[6], and scales the app across as though the two panels were a single surface ^[8]. Apple owns that transition. The layout it lands on belongs to whoever shipped the app.

Split View is where the app-side work sits. It runs two apps side by side or two windows of the same app, saves those pairs for reuse, and keeps a Siri AI conversation going next to whatever is on screen ^[9]. Two windows of one app is the part that needs a product decision. A mail client with a list beside a draft has to be built.

The camera features are the pitch. Smart Take fires the shutter when subjects look ready, Duo Preview makes the outer display a live viewfinder, and Kid Cue plays cartoons on the cover screen to hold a toddler's attention; Digital Trends says none of these dual-screen tricks exist on the Fold 8 ^[17]. None of them asks a third-party team for code either. The same goes for the Dock and the Dynamic Island sliding aside ^[15] and for the Duo's StandBy mode ^[14].

Digital Trends' reviewer wrote of the inner display that "It's not like the crease isn't there or isn't visible at all, but it doesn't fight you the way it does on most rivals, including the Fold 8" ^[3]. Samsung keeps the advantages a user feels in a pocket. The Fold 8 weighs 201 grams against the Duo's roughly 254 ^[4], a gap of 53 grams, about 26 percent more mass to hold up one-handed ^[16], and Samsung's phone is the slimmer of the two when unfolded ^[10].

On software, the same review is blunter than Apple's framing. "Samsung has had mature multi-window and Flex Mode on its foldables for years, so this is Apple playing catch-up rather than leading," Digital Trends wrote ^[11]. For a team that already maintains an Android tablet or Fold layout, the interaction model arriving on iOS is one their design system has probably answered once.

What the review does not carry is anything a planner can size work with. Digital Trends says it focused on the practical aspects that shape day-to-day use with foldables ^[5], and it names no APIs, no adoption numbers, and no prices beyond putting the two phones in the same bracket ^[1]. The Duo's features sort into two columns before sprint planning. Column one is what happens whether or not anyone does anything: the unfold animation, the scale-across, the Dock behaviour, Apple's own camera work. Column two is what only happens if you build it: how your layout uses the width, whether a second window of your own app is worth having, and what Pencil input means in your app once it lands. The first item in column two is the one worth building. The cost of that call is that you ship it without knowing how many Duos are in hands, because the comparison offers no usage figures for either phone ^[5].