Big Idea

The argument in one line.

Claude Code's new built-in iOS simulator plus a structured skill pack (planner, design system, build, launch checklist) lets one person spec, design, and build 70-90% of a native iOS app in a single sitting without leaving the chat.

Who This Is For

Read if. Skip if.

READ IF YOU ARE…

You want to build a native iOS app with an AI coding agent and don't want to juggle a separate simulator window.
You already have Xcode and an Apple developer account and want a repeatable process for going from idea to a working app preview.
You're interested in structured 'skill' systems (product planner, design system, build loop) that turn a vague app idea into a PRD and roadmap before any code is written.
You want to see a realistic, unpolished first-pass build (including the bugs and missing pieces) rather than a highlight reel.

SKIP IF…

You're building a web app only — this is iOS/Swift-specific and centers on the iOS simulator integration.
You don't have Xcode or an Apple developer account, since several steps assume both are already installed.

TL;DR

The full version, fast.

Claude desktop app now has a built-in iOS simulator panel, so you can watch a native Swift app render live while Claude Code writes it. The video demos this by building Dream Lock, a screen-lock journaling app, using a packaged skill system called BuilderOS: a product-planner skill interviews you to produce a PRD and phased roadmap, a design-system skill pulls a visual style from a Dribbble reference image, and a build-MVP skill executes the roadmap phase by phase with code review and testing between phases. The result is roughly 70-90% of a working app — home, journal, settings, and pause-point screens with a matching design system — built in about 15 minutes of chat time, with the remaining gaps (missing app-selection data, unconfigured Sentry/RevenueCat keys, App Store Connect setup) left for manual polish and device testing.

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Chapters

Where the time goes.

00:00 – 01:13

01 · Cold open

States the video's promise: build a full mobile app using Claude Code's new iOS simulator, BuilderOS skills, and a live demo.

01:13 – 03:03

02 · Installing BuilderOS into a new project

Opens a fresh folder ('DreamLock test'), pitches the DreamLock app concept (a screen-lock journaling twist on existing lock apps), and asks Claude Code to install the BuilderOS skill pack.

03:03 – 04:38

03 · Setting up the iOS simulator inside Claude Code

Shows where the iOS simulator panel lives in the Claude desktop app (three-dot menu) and walks through the Xcode/simulator installation check.

04:38 – 07:28

04 · Product planner skill: building the PRD

Runs the product-planner skill, answering its interview questions on target customer, core problem, business intent, and tech stack to generate a PRD and roadmap.

07:28 – 08:34

05 · Sponsor break: Product Studio program

Pitches his paid Product Studio coaching program for going from app idea to paying customers.

08:34 – 10:19

06 · Reviewing the roadmap and starting the build

Shows the generated PRD and roadmap (3 phases, ~42 tasks) and kicks off the build-MVP skill in a new session.

10:19 – 11:24

07 · Adding a Dribbble design reference

Grabs a mindfulness-app screenshot from Dribbble mid-build and pastes it into Claude Code as a visual reference for the front-end design.

11:24 – 12:51

08 · Attaching the iOS simulator

Opens the iOS simulator panel, attaches an iPhone 16 device, and watches the build complete with the simulator live on screen.

12:51 – 15:32

09 · Touring the finished Dream Lock app

Walks through the built app's home, journal, settings, and pause-point screens and the generated design-system HTML file, then finds first-pass bugs (empty app-selection list, missing back button, unconfigured keys).

15:32 – 17:19

10 · Wrap-up and community pitch

Recaps the process, plugs the BuilderOS community and his coaching program, and signs off.

Atomic Insights

Lines worth screenshotting.

Claude desktop's new iOS simulator panel renders a native app preview inside the same window as the coding chat, removing the need for a separate Xcode simulator window.
The demoed workflow builds a screen-lock journaling app called Dream Lock in about 15 minutes of chat time, reaching an estimated 70-90% complete state.
A 'product planner' skill interviews the builder — target customer, core problem, six-month vision, tech stack — before generating a PRD and a phased roadmap document.
The roadmap for this app was broken into 3 phases covering roughly 42 individual build tasks.
Pasting a single Dribbble reference image and asking the agent to match it produced a full design system (colors, typography, radius, components) documented in a design.html file.
The build-MVP skill executes the roadmap phase by phase and runs code review and tests after each phase completes, rather than writing the whole app in one uninterrupted pass.
Even a mostly-complete AI-built app surfaced concrete gaps on first run: an app-selection screen with no selectable apps, a missing back button, and unconfigured production keys (Sentry, RevenueCat).
Shipping to the App Store still requires manual steps outside the agent loop: physical device testing, App Store Connect setup, and a Family Controls distribution entitlement request from Apple.
The presenter recommends running a dedicated design-system skill before building, rather than a single reference image, for anyone who wants tighter visual control than this demo used.

Takeaway

A skill pipeline plus a live simulator gets an app to 80% in one sitting.

WHAT TO LEARN

Splitting an AI app build into planning, design-reference, and phased-execution stages produces a mostly-working app fast, but the last 10-20% still requires manual testing, keys, and platform setup.

02Installing BuilderOS into a new project

A packaged skill system can be installed into any fresh project folder with a single instruction, giving the agent a repeatable process instead of ad hoc prompting.
Picking an app idea that twists an already-proven category (screen-lock apps) lowers the risk of building something with no validated demand.

03Setting up the iOS simulator inside Claude Code

Viewing the simulator in the same window as the code chat removes the friction of switching between a separate Xcode simulator and the coding tool.
Xcode and the iOS simulator still have to be installed separately through the Mac App Store before the in-chat panel can render anything.

04Product planner skill: building the PRD

Answering structured planning questions (target customer, core problem, business intent, go-to-market) before coding produces a PRD and roadmap the build phase can follow.
Naming a specific primary customer persona up front (rather than a vague broad market) shapes which features the roadmap prioritizes.

06Reviewing the roadmap and starting the build

Breaking the roadmap into phases (here, 3 phases and about 42 tasks) gives the build skill natural checkpoints for review and testing.
Reviewing the generated PRD and roadmap before kicking off the build catches scope problems while they're still cheap to fix.

07Adding a Dribbble design reference

A single strong reference image, pasted mid-build, is enough to steer an agent's front-end design choices toward a specific visual style.
Running a dedicated design-system step before building (rather than a one-off reference image) gives tighter control over the final look, at the cost of extra setup time.

09Touring the finished Dream Lock app

A phased, reviewed build can reach a genuinely usable multi-screen app (home, journal, settings, pause-point) with a coherent design system in around fifteen minutes.
First-pass AI builds routinely leave concrete gaps — here, an app-selection list with no data and a missing back button — that only show up once you actually click through the app.
Production-readiness items like Sentry, RevenueCat, and platform entitlement keys are typically left unconfigured by the initial build and need to be added manually before shipping.

Glossary

Terms worth knowing.

BuilderOS: A packaged set of Claude Code skills (idea generation, product planning, design system, MVP build, launch checklist) that can be installed into any project folder to run a full app-build process.
Product planner skill: A guided Q&A skill that interviews the builder about target customer, problem, and business plan, then generates a PRD and a phased product roadmap document.
Build MVP skill: A skill that executes a roadmap phase by phase, writing code, then running code review and tests after each phase before moving to the next.
Family Controls distribution entitlement: An Apple-granted permission required for apps (like screen-lock apps) that need to monitor or restrict usage of other apps on the device; it must be requested from Apple before App Store submission.
PRD: Product Requirements Document — a written spec of what an app should do, generated here by the product planner skill before any code is written.

Resources

Things they pointed at.

02:13productBuilderOS (builder-os.dev) ↗

10:19toolDribbble ↗

07:36productProduct Studio (coaching program)

16:56channelBuilderOS community (school.com/aiapps, spoken as 'inschool.com/aiapps')

14:10toolSentry

14:11toolRevenueCat

Quotables

Lines you could clip.

00:00

“Anthropic just brought an entirely new way of building mobile apps to Claude code by introducing the iOS simulator in the Claude desktop app.”

clean statement of the video's news hook→ TikTok hook↗ Tweet quote

22:29

“The build MVP skill is designed to basically build, like, 70 to 80%, maybe even 90% of the app here, and then we just polish the final things.”

honest, quotable framing of what AI app-building actually delivers→ newsletter pull-quote↗ Tweet quote

The Script

Word for word.

Read-along

Don't just watch it. Burn it in.

See every word as it's spoken — crank it to 2× and still catch all of it. The same dual-channel trick behind Amazon's Kindle + Audible.

00:00Anthropic just brought an entirely new way of building mobile apps to Claude code by introducing the iOS simulator in the Claude desktop app. And so now you have the ability to view the iOS simulator inside of the Claude desktop app whilst you're working with Claude code so that when you're building mobile apps you can also see the preview of the app that you're building inside of the Claude desktop app.

00:21In this video, I'm gonna show you exactly how to set this up and use it so that you can start building mobile apps today. We're gonna go through how to build mobile apps with Claude code including how to set up my own system for building apps builder OS, how to use the iOS simulator inside of Claude code, and also walk through the full app building process and a demo of the app that we build through this process.

00:42If you don't know me, my name is Chris and for the last fifteen years been designing apps and advising startups on product and design. And if you are building websites like apps with AI, I've got a community where I've helped hundreds of people build and launch real websites and apps and get real customers. And you can check that out in the description down below if you're interested.

00:58Otherwise, let's get straight into the video and start building an iOS app with Claude code. So the first thing that I'm gonna do here is I'm just gonna set up BuilderOS inside of a project in Claude code. So I've gone to builder-os.dev and this set this system BuilderOS is basically my set of skills for building a full application from start to finish regardless of whether that's in mobile or a desktop or a web app.

01:21Basically just gives you all the skills you need from generating the idea, validating the idea, creating your design system, planning your product, building your MVP and building any features as well as launching and deploying your idea gives you all of the skills that you need to be able to do this inside one single operating system that you can set up in any new project with any coding agent that you're using regardless of whether that's Clawd Code, Codex or Cursor.

01:45So what I'm gonna do is copy this command here. I wanna jump over to Clawd Code in the desktop app. We're gonna choose a new folder to build this project in.

01:54I'm gonna open up this folder called DreamLock test. We're be building a mobile app which basically is a version of a screen lock app but basically where you get prompts for reflection or gratitude kind of journaling. Whenever you've used your phone for a certain amount of time, so the screen will get locked and then you'll be asked a certain prompts in order to reflect on something you've done that day or something that you're grateful for.

02:17Basically, just to break up the do scrolling with something positive in your day that you can reflect on and the kind of a twist on the prayer lock and all of the other screen lock apps out there. But just to also show you how you can take these ideas that are working already and just apply a different twist to it or something that you think would be useful in order to build something that's gonna work and be able to get customers.

02:39Because we wanna build something, especially if you're building mobile apps, a mold alliance of something that is already proven, something that already exists out there that has a proven customer base that we know is gonna be something that is gonna work. And so now I've opened up this DreamLock test folder. Let's just ask Claude Poe to install the Builder OS skills inside of this project.

02:59Can you install the Builder OS skills inside of this project? And then I'm just gonna paste the repository here. I'm gonna send that off to Claude code.

03:07I've got this set to fable five and high. You don't need to set it at this level really for just setting up Gulner OS but I am gonna use Fable five with high effort to build our mobile app here. And whilst we're waiting for this to install the skills, if you're wondering where to find the iOS simulator in the Claude desktop app, you just go to these three dots up here and then click on iOS simulator and that is how you get up your iOS simulator for the projects that you're working on.

03:33You'll see for now this is not gonna show anything here because we don't have an app inside of this repository. So the moment we don't have anything here because we haven't built an app inside of this repository. This will check your iOS simulator setup.

03:45If you do this as well and so if you don't have Xcode installed, you do need to run the simulator. Have to be at a you have to first install x code and then install the iOS simulator so that you can access both of these. All you would do is click open Mac app store.

03:59It's gonna take you to the x code page here in the app store and allow you to install x code and the iOS simulator. For mine, this is already installed here. It's just checking the x code installation and the simulator installation.

04:12This is where we're gonna see the preview of our mobile app on the right hand side here. So let's close that for now and go back to port code in this project. And what we're gonna do here is we're going to run the product planner skill in order to plan our product first.

04:25And this is gonna help us to create the PRD and the road map documents that we're gonna need to actually build our app from scratch and build it all in one go. So what I'm gonna do here is I'm just gonna say to Claude code in a new session, use the product planner skill in this project to help me plan my app.

04:44And that is going to find the product planner scale that we've just installed inside of this project. And then it's gonna run it and what the product planner scale does is it basically guides you through step by step asking all of the questions that you need to basically create your PRD and your robot documents so that you can build your app in one go.

05:01And this is gonna build like 70 to 80% of the app in one go with us being able to then do the final sort of 10 to 20% polish on top of that. So the first question it's gonna ask here is what do you want to build? Now it says a dream journaling app called DreamLoc.

05:15I'm just gonna give it some idea on what I'm actually wanna build here. I wanna build a mobile app for iOS in Swift called DreamLoc that will lock the screen after a certain amount of time that the user is on their phone and would give them a prompt for a gratitude recognition or some sort of reflection in order to break up doom scrolling with something that's more positive for the user.

05:44So I'm gonna send that off to Claude Coat here. And now the product planner skill is gonna take us through more questions to get an even deeper understanding of the price that we wanna build, and it's also gonna suggest to us some different directions that we might wanna go in order to add or remove features to this and define our MVP.

06:00So let's just go through and answer some of these questions and I'll jump in and out based on what's relevant here so that we can get to our PRD and our roadmap document. So what the product planner skill is also doing is helping us to identify our target customer. So what I'm gonna go for, you got burned out knowledge workers, mindful parents, wellness minded young professionals.

06:18I'm gonna go for number one here which is wellness minded young professionals as the primary customer. And the problem that I'm solving here is this beauty calorie time drain problem.

06:28Basically, hours vanish into feeds and leave nothing behind. No rest, no learning, no joy. And so we're trying to insert a moment of joy and learning and self reflection into that do scrolling session.

06:40So I think it's number three here. So now we're getting towards the end of the product planner set of questions here. I've answered a bunch of other questions going through this based on six month vision, ninety day success, what the business intent for this app is, what's broken about the current option, these current alternatives people are using, secondary customer personas, as well as a basic idea of my go to market plan and my brand voice that I'm gonna be using it and tone of voice I wanna use in this app as well.

07:07So let's finish up these questions here. So now we finished answering all the questions inside this product planner skill including the tech stack from payments to back end and database to the tooling that we're gonna use to actually build it.

07:21Claude Co. Is now gonna create our product vision and our PRD and road map documents so that we can start building this full application. Quick break in the video to talk about how you can make five to 50 k from your app or product idea inside of my program, the product studio.

07:36Now in the product studio, I teach people the exact process to go from idea to live products with real paying customers. The program walks you through the entire process from start to finish, from finding the right idea, figuring out the business strategy, building your design system and product identity, to building the full product with AI coding agents, and launching it to real paying customers with a strategy that is tailored to your specific products.

08:01Plus you get a load of ongoing support to help you actually reach that five to 50 k target as well. So if you're interested in learning more about how you can launch your products and make between five to 50 k, then you can click the link in the description down below to apply to the product studio. And I'll see you there.

08:18Let's get back to the video. So now the product planner and builder OS has created our PRD and our roadmap for us. So we've got our PRD document here that we can use to actually build this app and we've got the product roadmap document here as well which is broken down into phases.

08:34So each phase is a set of tasks here that our AI coding agent, and Claude code in this case, is gonna go away and build individually. And we can just use the build MVP skill inside of BuildOS to build this full app. And what that's gonna do is that's not only gonna build through each of these tasks one by one but it's also gonna do code review and test each of the phases after it completes each phase as it goes as well.

08:58And you can see here we've got how many phases have we got here. We've got three phases here so not too difficult for an app build. This should be pretty quick to kinda go through about 30 to 40 different tasks, about 42 different tasks here to build through.

09:13So let's close this and now open a new session in this project and we're just gonna say to Claude code here, build the full app using the build m v p scale in this project. And I've got this using Fable five and higher as well but I think Opus five is also just about to come out so you could use Opus five for this legitimately as well.

09:33I think Opus five is gonna have a really really good benchmarks and it's gonna be a great daily driver model for most people. So if you're doing this after Opus five has come out, you can also use Opus five for this.

09:47Now this is found the build m d p skill and I'm gonna always allow this It's gonna get started building our app here. And then after it's built the app following the road map and the PRD, we're gonna be able to open iOS simulator to see how this works, look at our look at our app, and make any changes as well. There's one thing that I also wanna do here before this gets running.

10:07So I'm actually gonna stop this. What I wanna do alongside this as it builds it is to add in a visual reference that we can do for this mobile app. So what I'm gonna do is I'm gonna go to dribble.com.

10:19I'm just gonna find some examples of mindfulness apps, similar sort of relaxation mindfulness apps that I want to kinda use as a reference for this mobile app.

10:30So I actually quite like this visual style here with kind of the background kind of gradients with the texture and then this serif font on these white kind of cards with illustrations as well. So what I'm gonna do is I'm gonna go back to Claude. I'm gonna paste this in and then I'm gonna just say build the full app using the build MVP skill and use this image reference for the entire front end design of the app.

10:54Now what I could do instead of this is actually to create a design system before I build the full application here. But for the purposes of this video, I'm just gonna use an image reference because that's easier and get it to build following the image reference instead. I would a 100% recommend using the design system skill inside of BuilderOS though, where before you actually start building your app.

11:14So now that Claude code has got this. It's gonna go away and build the full application following the PRD and the roadmap and let's see what it comes back with in the iOS simulator. So whilst this is installing, I'm gonna get the iPhone simulator, the iOS simulator set up in Claude code and I'm just gonna tap this iOS simulator button in the top right here.

11:33And then this has found the x code and the simulator is installed. So let's click attach simulator here. We can choose the device that we want to attach the simulator with.

11:42So I'm gonna go for iPhone 16. We're gonna click allow and then allow. And then this is gonna get the iPhone simulator started inside of for us so that we can preview our projects that we're building here.

11:55So now ClawCode has gone through our entire app builder. It's also run the design system scale for us using this image reference. So we have our mock up of our app on the right hand side.

12:06And you can see here you even have the liquid glass style navigation in the bottom which matches the latest kind of Apple guidelines for user interface. And we have our entire app following this design system here.

12:21And if we open up the design system in this design dot HTML file, you can also see the design system that has pulled together for us for this app including the background gradients, all of the colors it uses here, typography rules, radius components, and this is all done using the design system skill inside of Builder OS.

12:43And that has done that for us on all side building our MVP here of this mobile app. And we're running this now on the iOS simulator inside of Quorn code.

12:53And this has just taken, you know, gone through the product planner skill and answered all the questions, created the PRD and the road map, and then just run the build MVP skill. And it has built this entire app for us called DreamMoc. So we have our home screen here.

13:09We have our journal screen here where we have all of our reflections basically inside of this app. We have our settings screen here where you have your apps which is the ones that we're allowing DreamWalk to basically add the screen lock functionality to.

13:25So you have all of your different apps here and all the categories. I'm gonna close this and we're gonna go back here.

13:31We have the pause point, so how long we are allowing DreamWalk to basically to run this screen lock feature.

13:41And this is all like you can even hear the clicking sound there, all native and Swift UI. Let's click continue.

13:49And the design is incredibly good. There are some things I might wanna change here like this Sans Serif heading font.

13:55Let's just use the Serif font instead. But overall, they have a really really solid app design, has everything connected that we needed to.

14:04It's given us some things that we do need to do here. So the fam file, the family controls distribution entitlement request, Apple today.

14:12Keys, we also need keys for Sentry, revenue cap public key, postal key, and plus a development team in this file here, unconfigured b bug builds, keep the loop testable. We also need physical device passes here for some of these tasks.

14:25So we do need to test it on our own device to test that it works. And we need to set up App Store Connect, which if you have an Apple developer account, you've got that. And then we can just basically run the onboard checklist skill inside of Builder OS to give us the exact steps to deploy this app to the App Store.

14:41So that's it. We're gonna choose the apps here that we wanna do screen lock for. So I'm gonna choose social and have that set to all.

14:49There are actually no apps on this that we can select. So we might wanna add some here to test because we're doing I'm clicking continuing area. It won't actually allow us to go past this screen.

14:58So there are some things we need to fix here. That's completely fine. The build and l p skill is designed to basically build, like, 70 to 80%, maybe even 90% of the app here, and then we just polish the final things and do and and basically test that it works after we've built it and then fix any issues that we find here.

15:16We also need to add a back button on this so that we can get back to the home screen if you want to as well. You can see in here we've got our full mobile app built pretty much 80% of the way there, all just all using Claude code and the new iOS simulator.

15:32And now we can continue to work on our app from inside of Claude code, running the simulator inside of Claude code as well so that we have visibility of everything that is going on inside of our app. And if you use a system like Lord OS, this is something that you can legitimately build in less than a day as well. Get your app up and running, connect everything, submit it to the App Store, get it into App Store Connect, test it on your phone, and all you have to do is go through those skills inside of BuilderOS, the product planner, the build MVP skill, and then the launch checklist to actually get your app ready to to actually get your app ready and submitted to the app store.

16:06So now that we've gone through the full build here, let me get into my final pause. So you can see how easy it is now to build full mobile apps, native iOS apps in Swift inside of Claude code using the iOS simulator directly inside of the Claude code interface on the Claude desktop app. And this just makes it so much easier to develop and build mobile apps inside of Claude code without having to run all these different things separately or have a separate window for your iOS simulator.

16:34It may seem like a small thing, it just makes the entire process easier. And if you use a system like BuilderOS, you're gonna have a really straightforward path to actually specking your entire app, building it in one go with the build MVP skill, and then figuring out exactly how to launch it with the launch checklist skill as well.

16:51And if you wanna learn exactly how to use BuilderOS, you can learn about it inside of my community over inschool.com/aiapps. And if you wanna understand how to build an app and launch it and make five to 50 k or more with that idea, then I run an exclusive coaching program to guide people through this process which is currently open for applications, and you can find the link to apply to that down in the description below as well.

17:14If you enjoyed the video, don't forget to like and subscribe. Thank you for watching, and I will see you next time.

The Hook

The bait, then the rug-pull.

Claude's desktop app just gained a built-in iOS simulator panel, and this video treats it as a reason to build a real app on camera — from a blank folder to a working screen-lock journaling app called Dream Lock, using a packaged skill system to generate the spec, the design, and most of the code in one sitting.

Frameworks

Named ideas worth stealing.

02:13list

BuilderOS skill pipeline

idea generator
product planner
design system
build loop / build MVP
launch checklist

A set of Claude Code skills meant to be installed into any project (works with Claude Code, Codex, or Cursor per the presenter) that carries an app from idea validation through PRD, design, MVP build, and launch prep.

Steal forstructuring any AI-assisted build so planning and design happen before code, with a checklist-driven build phase

CTA Breakdown

How they asked for the click.

VERBAL ASK

07:36product

“click the link in the description down below to apply to the product studio”

Mid-video sponsor-style break for his own paid coaching program, plus a second CTA at the very end for both the BuilderOS community (school.com/aiapps) and the same coaching program.

MENTIONED ON CAMERA

02:13productBuilderOS (builder-os.dev) ↗

10:19toolDribbble ↗

FROM THE DESCRIPTION

PRIMARY CTAWhere the creator wants you to go next.

OTHER LINKSAlso linked in the description.

Storyboard