DS and 3DS on the iPhone Duo: What Actually Works on Apple's Foldable

2026-10-26 · Setup guide

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The iPhone Duo went on sale on 23 October 2026. Delta 2.0 landed the day before it, with support built specifically for the fold. For the first time, a phone is physically shaped like the console a lot of people most want to emulate on it.

The DS half of this genuinely delivers. Two screens, a hinge in the right place, and the game sleeps when you close it.

The 3DS half does not, and the gap between the two is bigger than any of the launch coverage suggested. There is exactly one 3DS emulator on the App Store, it costs $2.99, and its most recent update shipped nearly three weeks before the iPhone Duo existed.

Here is the honest state of both, plus the setup, and one buying trap that will cost you $50 if you get it wrong.

The Short Version

• DS works beautifully. Delta 2.0 is free, supports the fold properly, and puts the game on top with touch controls below.
• Close the lid and the game sleeps. Exactly like a real DS.
• 3DS works, but with no foldable support at all. Folium is the only option, it is $2.99, and its last update predates the device.
• Delta still has no 3DS core and never has. The two apps do different jobs. You will want both.
• Apple Pencil works as a DS stylus, but not with every Pencil. You need the Apple Pencil (USB-C). The Pencil Pro will not work.
• Pencil support needs iOS 27.2, which was not on the device at launch.
• Sega Genesis in Delta is not free. It needs Delta's paid tier. Every Nintendo system, DS included, is free.
• This is a $1,999 phone. A dedicated dual screen handheld does the DS job for a fraction of that.

Which App Does What

The two apps do not overlap much, which is why most people end up with both installed.

If you only want DS, you only need Delta, and it costs nothing. If you want 3DS, Folium is the only route on an iPhone and there is no competition to switch to.

DS on the iPhone Duo: This Part Is Genuinely Good

Delta 2.0 shipped on 22 October 2026, one day before the phone. The developer called it the biggest update in the app's two year history, and the fold support is the headline.

What it actually does:

• The upper panel shows the game. The lower panel becomes the touch screen and the controls. That is the DS layout, on a device with a hinge between the halves.
• Controls re-lay out as you move the hinge. Half folded on a desk, flat open, or propped in tabletop mode, the virtual buttons move to match.
• Close it and the game sleeps. This is the detail that made people care, and it is the right call. Shutting a DS lid paused the game. Shutting the Duo does the same thing.
• Animated controller skins, so the on screen buttons are not just flat rectangles.
• RetroAchievements, which adds unlockable achievements to games that never had them.
• A redesigned library with favourites and recently played sections, plus optional CRT style filters.

Delta is free on the App Store, with no ads in the emulation itself. In the EU it is also on AltStore PAL.

One thing to be clear about, because our own earlier article needed the same correction: Sega Genesis is the one system in Delta that is not free. It needs Delta's paid tier, which you can unlock either as an in-app subscription through the App Store or, in some regions, through the developer's Patreon. Every Nintendo system in the app, including DS and N64, is free.

The Orientation Decision Nobody Explains

This is where a little arithmetic helps, because the two ways of holding the phone pull in opposite directions. We ran these numbers ourselves.

The Duo's inner display is 1878 by 2670. The cover screen is 1398 by 2034. A single DS screen is 256 by 192, and two of them stacked make a 256 by 384 image.

For pixel art you want integer scaling, which means multiplying every pixel by a whole number. Every pixel stays the same size and shape. A fractional number duplicates some pixels and not others, which is where that faintly smeared look comes from.

Normal portrait, crease running vertically. The full inner display takes a stacked DS image at 6x, which is 1536 by 2304. That is an enormous DS image, far past what any slab phone manages. The catch is that the crease now runs straight down the middle of both DS screens. You have put a vertical seam through the centre of every sprite.

Rotated, crease running horizontally. Each half of the inner display is now roughly 2670 by 939, and the hinge sits exactly where a DS hinge sat. This is the arrangement the whole idea is built around. But each DS screen is limited by the height of its half, so you get 4x, which is 1024 by 768 per screen. You will have wide black bars either side.

So the sharper image and the better ergonomics are not the same setting. Rotated is what you want for a long session. Portrait is what you want for a screenshot.

No aspect ratio saves you either way. Both of the Duo's panels are close to 1.43. A stacked DS image is exactly 1.5. Some letterboxing is unavoidable.

For reference, the cover screen fits a stacked DS image at 5x, which is 1280 by 1920. That is a good DS experience on a closed phone, which is a strange sentence to be able to write.

The Apple Pencil Trap

A stylus on a dual screen device is the obvious pairing, and the iPhone Duo is the first iPhone that takes an Apple Pencil at all. Two things will catch people out.

It did not work at launch. Apple Pencil support is not in the software the phone shipped with. It arrives in iOS 27.2. That update was in release candidate on 21 October and was expected to go public around 26 October, so check Settings before you buy anything.

Only one Apple Pencil works. The iPhone Duo supports the Apple Pencil (USB-C) model. Other models, including the more expensive Apple Pencil Pro, are not compatible. This is the expensive mistake, because the Pencil Pro is the one most people would assume is the better buy.

Once it is live, Pencil input works on both the inner and the outer display. For DS games built around the stylus, which is a long list, that is the closest anyone has got to the original input on a phone.

3DS on the iPhone Duo: The Honest Answer

This is the half the launch coverage skipped, so here it is plainly.

Folium is the only 3DS emulator on the App Store. It is $2.99, it covers 3DS along with DS, the Game Boy line, NES, SNES, PS1, Genesis, WonderSwan and ColecoVision, and it needs iOS 16 or later.

It has no iPhone Duo support. Its most recent version is 2.2, released on 4 October 2026, which is nineteen days before the iPhone Duo went on sale. Nothing in its update history mentions foldables, the fold, or dual screen layouts. What that means in practice is that a 3DS game on a $1,999 foldable gets the same treatment it gets on a regular iPhone, letterboxed into whichever panel you are using, with the crease wherever the crease falls.

That is not a knock on the app. Folium 2.2 added useful things, including working analog stick support for PS1 and new graphics settings for the handheld systems. It simply has not been updated for hardware that did not exist when it shipped.

Delta will not fill this gap. Delta has never emulated the 3DS, has no 3DS core, and has not announced one. The systems it covers are NES, SNES, N64, Game Boy, Game Boy Color, GBA, DS and Genesis. That is the whole list.

So the realistic expectation: buy the Duo for DS, and treat 3DS as something that works rather than something that shines. If Folium ships fold support later, that changes. It has not yet.

If 3DS is your priority rather than a bonus, the honest recommendation is different hardware. Best handhelds for DS and 3DS emulation covers devices built for two screens, and several of them cost less than a tenth of this phone.

Setting It Up

Both apps follow the same shape. This assumes you are playing games you already own and have dumped from your own cartridges.

Delta, for DS

1. Install Delta from the App Store. It is free.
2. Get your games onto the phone. The easiest route is the Files app. Put your DS files in a folder in iCloud Drive or On My iPhone, then import them from inside Delta.
3. Add DS system files if your games need them. Some DS titles want the console's own BIOS files to boot correctly. Delta will tell you if a game needs them. You dump these from a DS you own.
4. Open the phone and pick your orientation. Try it rotated first, with the crease horizontal. That is the layout the fold support was designed for.
5. Set up controls. Delta's skins adapt to the fold position, but you can still move things. If a game is stylus heavy, leave the lower panel clear.
6. Turn on save sync if you want to carry saves between an iPhone and an iPad.

Our full walkthrough with screenshots of each step is in the Delta setup guide.

Folium, for 3DS

1. Buy and install Folium, $2.99 on the App Store.
2. Import your 3DS games the same way, through the Files app.
3. Expect to tune the graphics settings. 3DS emulation is far heavier than DS, and Folium 2.2 added new graphics options specifically for the handheld systems. Start conservative.
4. Do not expect a fold aware layout. Pick whichever panel gives you the larger image and accept the letterboxing.

The A20 Pro chip in the Duo is the fastest thing Apple has put in a phone, so performance is not the limiting factor here. Layout is.

What to Buy Alongside

Three things make a real difference, and one of them is the Pencil above.

A controller. For anything that is not stylus based, physical buttons beat glass. Both apps support the usual suspects, including DualSense, Xbox Series controllers and the Backbone One.

A stand. Tabletop mode is the mode that makes this feel like a DS, and the phone will hold itself at a shallow angle but not a comfortable one for long sessions.

A case made for the fold. Worth saying only because a case that fights the hinge will ruin the whole point. Check it is cut for the Duo specifically.

Is a $1,999 Phone the Right Way to Play DS Games?

No, and it is worth being straight about that.

If the DS library is what you want, a dedicated dual screen handheld does the job properly for a tiny fraction of this. There are devices built around two screens, and there is a dual screen add on for the Retroid Pocket line that we covered in the Retroid dual screen add on piece. Those exist specifically for this.

The Duo makes sense if you were buying a foldable anyway. Then Delta 2.0 is a free bonus that happens to be the best DS experience available on a phone, by a wide margin, and that is a genuinely nice thing to get for free.

What it is not is a reason to spend $1,999.

What to Watch

• Whether Folium adds fold support. This is the single thing that would change the 3DS answer. It has had nineteen days less notice than Delta did.
• Whether Apple Pencil input lands in Delta specifically. System level Pencil support in iOS 27.2 is not the same as an app choosing to use it for a stylus game.
• Whether a 3DS layout can even work here. A 3DS has a wide top screen and a narrow bottom one, not two matching screens. The Duo's two equal halves fit a DS far better than they fit a 3DS, which may be part of why nobody has rushed it.

Frequently Asked Questions

Can the iPhone Duo play Nintendo DS games?

Yes, and it is the best DS setup available on any phone. Delta 2.0 is free and was built for the fold. The game goes on the upper panel, touch controls on the lower one, the layout adapts as you move the hinge, and closing the phone puts the game to sleep like a DS lid.

Can the iPhone Duo play 3DS games?

Yes, through Folium, which is $2.99 and the only 3DS emulator on the App Store. But Folium has no iPhone Duo support. Its most recent version shipped on 4 October 2026, nineteen days before the phone went on sale, and nothing in its history mentions foldables. 3DS games get the same letterboxed treatment they get on a normal iPhone.

Does Delta support 3DS games?

No. Delta has never emulated the 3DS, has no 3DS core, and has not announced one. It covers NES, SNES, N64, Game Boy, Game Boy Color, GBA, DS and Genesis.

Which Apple Pencil works with the iPhone Duo?

The Apple Pencil (USB-C) model only. Other models, including the Apple Pencil Pro, are not compatible, which is an easy and expensive mistake to make. Pencil support also needs iOS 27.2, which did not ship on the phone at launch.

Is Delta free on the iPhone Duo?

Yes, with one exception. The app and every Nintendo system in it, DS and N64 included, are free. Sega Genesis needs Delta's paid tier, available as an in-app subscription or in some regions through the developer's Patreon.

How good do DS games look on the iPhone Duo?

Very good, and the answer depends on orientation. Held in normal portrait the inner display takes a stacked DS image at 6x, but the crease then runs down the middle of both screens. Rotated so the hinge sits between the screens, you get 4x per screen with bars at the sides. Rotated is better to play, portrait is better for a screenshot.

Should I buy an iPhone Duo for emulation?

Not on its own. At $1,999 it is a poor value proposition if DS games are the goal, and dedicated dual screen handhelds do that job for a small fraction of the price. If you were buying the phone anyway, the DS support is an excellent free extra.

Do I need the games on the device, or can I stream them?

They need to be on the device. Both apps import files through the Files app, from iCloud Drive or local storage. You should be playing games you already own and dumped yourself.

Is emulation allowed on the App Store now?

Yes. Apple changed its rules in 2024 and both of these apps are approved, listed and updated through the normal App Store. Folium has been the only approved 3DS emulator since it arrived.

Related Reading

• Delta 2.0 Brought iPhone Duo Support. It Still Will Not Play 3DS Games
• Delta Emulator Setup Guide for iPhone
• How to Emulate Retro Games on iPhone
• Best Handhelds for DS and 3DS Emulation
• The Retroid Dual Screen Add On for DS and 3DS
• Dual Screen Handhelds in 2026
• melonDS Setup Guide

Written 26 October 2026. Delta 2.0's feature list and release date come from the developer's own announcement and store listing. Folium's price, version, update date and system list come from its App Store listing, retrieved the same day. iPhone Duo panel resolutions are Apple's published figures and all scaling arithmetic is our own. Apple Pencil support arrives in iOS 27.2 rather than the software the phone shipped with, so check your software version before buying a Pencil. We have not tested Apple Pencil input inside Delta.