How to Build an iOS App in 3 Weeks with an AI Assistant

8/10/2025

From Idea to App Store: How I Built a Complete iOS App in 3 Weeks with Claude Code

Man, building an app is one of those things that always seems like a mountain to climb. You hear stories of teams taking months, even years, to get something out the door. So, if I told you I went from a simple idea to a fully functional iOS app on the App Store in just three weeks, you'd probably think I was either crazy or lying.

Honestly, a few weeks ago, I would've thought the same thing.

But here's the thing: the game has changed. AI is here, & it’s not just for writing emails or generating funny pictures. It’s a legitimate coding partner. I just spent the last 21 days in the trenches, building an app with Anthropic's Claude as my co-pilot, & it was a WILD ride. This isn't a "get rich quick" story, but a real-deal account of how I leveraged AI to do something that felt impossible.

The Big Idea & The Ticking Clock

Like most app ideas, mine started with a personal problem. I’m a huge podcast junkie, but I’m terrible at remembering the awesome book recommendations, tools, or random facts I hear. I wanted a simple app: start a timer when a podcast starts, hit a button to create a timestamped note, & jot down the good stuff. Simple, right?

The catch? I gave myself a hard deadline of three weeks. Why? Because I wanted to see if it was actually possible. Typical app development, even for a "simple" app, is estimated to be around 1 to 3 months. I wanted to slash that. I knew the only way to even have a fighting chance was to lean HEAVILY on an AI coding assistant.

Week 1: Planning, Prototyping, & Prompts

The first week wasn't about writing a single line of Swift code. It was all about planning. Rushing this stage is one of the biggest mistakes you can make. A solid week of planning can save you months of headaches later.

Ideation & Market "Research" (Days 1-2)

First, I fleshed out the core concept. I needed to define the user journey & core features.

Core Loop: Open app -> See list of podcasts -> Start a new session -> Tap a button to add a timestamped note -> Save & review notes.
Must-Have Features: Simple session timer, one-tap timestamping, text entry for notes.
Nice-to-Have Features: Ability to categorize notes, search functionality, maybe some color-coding.

I did a quick App Store search. Were there other apps like this? Yep, a few. But most were either too complex or part of a larger, paid podcasting app. I saw a niche for something hyper-focused & simple.

UI/UX Design with a Twist (Days 3-5)

This is where things got interesting. I'm not a designer. My artistic skills peak at stick figures. Normally, this phase alone can take 4-8 weeks, involving wireframes, mockups, & prototypes using tools like Figma or Sketch.

I decided to use Claude for this. I treated it like a junior designer.

My prompt went something like this:

"Hey Claude, I'm designing a simple iOS app in SwiftUI. The main screen will list podcast sessions. There needs to be a big '+' button to start a new session. The session screen will have a timer at the top, a text field in the middle for the current note, & a 'Timestamp & Save' button at the bottom. Below that, a running list of notes for the current session. Can you give me a simple, clean layout for this? Think minimalist, lots of white space, easy to read."

BOOM. Claude spat out a descriptive layout, suggesting using a

List

for the sessions, a

VStack

for the session screen, & even recommended specific SwiftUI components. It wasn't a visual design, but it was a blueprint. We went back & forth, refining the layout. I'd ask for tweaks, like "How would I add an icon to the timestamp button?" & it would provide the code snippet. This process of using conversational prompts is a game-changer for non-designers.

Setting Up the Dev Environment (Days 6-7)

This part is pretty standard. I got my Mac, downloaded the latest version of Xcode (Apple's official tool for iOS development), & registered for an Apple Developer Account. You need this account to get access to all the tools & eventually, to publish your app. I created a new Xcode project & was ready to roll.

Week 2: The Coding Slog, Supercharged by AI

This is where the magic (and the caffeine) really kicked in. The second week was dedicated to turning those design ideas into a functional app. Normally, this coding & development phase can take anywhere from 8 to 36 weeks. I had 7 days.

Building the Bones (Days 8-10)

I started with the core UI. I took the layout ideas from my "design session" with Claude & started building the screens in SwiftUI. I would describe a component I wanted, & Claude would generate the code.

For example, I needed a custom view for each podcast session in the list. I prompted:

"I need a SwiftUI view that shows the podcast name, the date, & the number of notes. It should be in a rounded rectangle with a subtle shadow."

Claude provided the complete SwiftUI code, including

HStack

VStack

arrangements,

Font

modifiers, & even the

shadow

effect. My job was to stitch these components together, test them in the Xcode simulator, & make sure they looked right.

Wiring Up the Logic (Days 11-14)

An app is more than just pretty screens. You need to handle data. This is where an AI partner is INCREDIBLY powerful. I'm talking about things like:

Data Models: I needed a way to structure my data. I asked Claude, "Create a Swift
1struct
to represent a PodcastSession, with properties for a name, a date, & an array of Note objects. The Note object should have a timestamp & a content string." Done.
Saving Data: I didn't want users' notes to disappear when they closed the app. I needed data persistence. I knew
1Core Data
or
1UserDefaults
were options, but I wasn't sure which was best for my simple case. I asked Claude. It explained the pros & cons & suggested
1Codable
with
1UserDefaults
was perfect for my needs, then provided the code to save & load my sessions.
The Timer: I needed a timer that updated the UI in real-time. This can be tricky with threading. I asked Claude how to build a timer in SwiftUI that updates a view every second. It gave me a solution using a
1Timer.publish
publisher, which is the modern way to do it.

Throughout this process, Claude wasn't just a code generator; it was a tutor. I could ask why a certain approach was better or what a specific line of code did. It's like having a senior developer on call 24/7. Studies have shown that AI tools can boost developer productivity by up to 55%, & I absolutely felt it.

It’s worth noting that many businesses are looking to implement this kind of AI-powered assistance for their own customers. For a lot of companies, building a custom solution is too complex. That's where platforms like Arsturn come in. It allows businesses to create their own custom AI chatbots, trained on their specific data. These bots can provide instant customer support, answer questions, & engage with website visitors around the clock, much like how I was engaging with Claude.

Week 3: The Final Polish & The App Store Gauntlet

The final week was a blur of testing, bug fixing, & navigating the infamous App Store submission process.

Testing & Bug Squashing (Days 15-17)

No app is perfect on the first try. This phase is CRITICAL. A buggy app gets deleted. Period. Normally you'd spend 2-6 weeks on Quality Assurance (QA).

My testing process was two-fold:

Me: I used the app constantly, trying to break it. I entered weird text, started & stopped sessions rapidly, & tried every button combination I could think of.
Claude: When I found a bug, I'd describe it to Claude. "My app crashes if I hit the 'Timestamp & Save' button before the timer is running." Claude would analyze the logic & often pinpoint the error, suggesting adding a check to disable the button until the timer was active. It helped me find & fix bugs SIGNIFICANTLY faster than I could have on my own.

Prepping for Launch (Days 18-19)

Getting ready for the App Store isn't just about code. It’s a whole checklist. You need:

App Icon: I used an AI image generator to create a simple, clean icon.
Screenshots: I ran the app in the Xcode simulator on different iPhone sizes & took screenshots.
App Description: I wrote a draft of the description & had Claude refine it for clarity & tone.
Privacy Policy: SUPER important. I prompted Claude with the features of my app (e.g., "it only stores user-generated data on the device itself") & asked it to generate a basic privacy policy. I then had a legal-savvy friend glance over it.

Submission & Review (Days 20-21)

This is the final boss battle. You submit your app through a portal called App Store Connect. Apple's review process is notoriously strict; they check for quality, security, & adherence to their Human Interface Guidelines. It can take a couple of days to a couple of weeks.

I filled out all the forms, uploaded my screenshots, & hit "Submit for Review." Then, I waited. It's a nerve-wracking feeling. After two long days, I got the email: "Ready for Sale."

I had done it. From a simple idea to a live app in 21 days.

Could I Have Done It Without AI?

Honestly? No. Not in three weeks.

The raw coding time would have been immense. The research for every little bug or feature would have taken days, not minutes. The design phase would have been a non-starter for me. Claude acted as a force multiplier. It handled the boilerplate, the syntax I couldn't remember, & the architectural questions that would have had me stuck for hours.

This isn't to say it was effortless. The AI isn't perfect. Sometimes it would generate outdated code or have a "hallucination" about a feature that didn't exist. You still need to be the "lead developer." You need to know what you want, understand the code it gives you, & be able to spot when something is wrong. But as a tool to accelerate the process, it's absolutely revolutionary.

This experience has me thinking about how businesses can leverage this kind of AI. Imagine a customer visiting a website & instead of a frustrating FAQ page, they interact with an AI that understands their problem. That’s the kind of solution Arsturn helps businesses build. It’s a no-code platform that lets you train an AI on your own business data, helping boost conversions & provide personalized customer experiences, making that instant, helpful interaction a reality.

So yeah, three weeks. It was a sprint, not a marathon. It was intense. But it proved to me that the barrier to creating software is lower than it has ever been. If you've got an idea rattling around in your head, there's never been a better time to try & build it.

Hope this was helpful & gives you a little inspiration. Let me know what you think