Claude Sonnet 4.6 Tutorial for Beginners: Build Apps with AI (2026)

Kristoffer · March 6, 2026 · 7 min read

Claude just dropped one of its best models yet - Sonnet 4.6. And most people have no idea what it's actually capable of.

This isn't just a slightly better model. Sonnet 4.6 can write better production-level code, perform tasks in very little time, and make decisions across an entire app like a senior engineer.

So in this tutorial, we're going to test it to its limits by building a Trello clone - a native mobile app - from scratch. By the end, you'll understand how Sonnet 4.6 destroys previous models, what it's actually good at, and whether it's finally good enough to build serious AI apps with.

The 6-Step Process

To build this app, we're going to follow a 6-step process - starting from validating the idea and making sure we're building something people actually want, all the way to publishing it on the Apple App Store.

But first, we need to make sure the app we're building meets this checklist:

  1. It must solve a frequent problem people have
  2. We must be able to explain the app in 3 words
  3. We must be able to make money from the app

The app that meets all three requirements? Trello. It has over 50 million users and makes $700 million a year.

To build an app like Trello - especially a native mobile app - you'd normally need a team of iOS and Android engineers and months of development. But what if I told you I cloned this exact app for mobile, in under 30 minutes, without writing a single line of code?

Step 1: Architecture with Opus 4.6

The first step is getting the architecture right. This is the step most people skip - and it's exactly why most apps look cool but make zero money.

For this, we're using Claude Opus 4.6. Opus 4.6 is currently the smartest model for reasoning and architecture. It sees things other models miss.

I uploaded a screenshot of Trello and told Opus to analyze it and produce an entire blueprint to follow. And it delivered - Opus analyzed the image and gave us a perfectly structured plan that breaks down:

With our blueprint ready, it's time to start building.

Step 2: Mobile Boilerplate Setup

Head over to mobileboilerplate.io. I like using this website because it solves all the problems of building auth, payments, backend, push notifications, and so much more - and it's very simple to use.

Just enter a brief description of your app, and mobileboilerplate.io will start generating a boilerplate specific to your needs. Once done, all you have to do is complete the setup process which takes less than 5 minutes.

Step 3: Building with Claude Code & Sonnet 4.6

Now for the magic.

Open the boilerplate in Claude Code and make sure it's running Sonnet 4.6. Sonnet 4.6 is the faster, more aggressive coding model - perfect for the heavy lifting.

Paste the prompt from the boilerplate and Claude Code will immediately start building the mobile app. It writes files and automatically installs every library needed to make the app function.

In just a few minutes, Claude Code says the app is ready to be installed on your iPhone. Follow its instructions:

  1. Copy the build command and paste it into a new terminal
  2. Log into your Expo account (free) and Apple Developer Account ($99/year)
  3. Wait for the build to complete - you'll get a QR code to scan
  4. Scan the QR code to trust your device
  5. Run the deployment command to build the app onto your phone

And just like that - the app is ready on your iPhone.

The boilerplate already created an onboarding process and an auth system without even being asked. This is one of the biggest benefits of using mobileboilerplate.io - something that would've taken days was done within seconds, and the boilerplate understood the exact needs without any extra instructions.

[!TIP] Make sure to disable email confirmation from Supabase when testing the app so you don't have to confirm your email during development. Go to your Supabase dashboard, click on Authentication, then "Sign In / Providers", and disable "Email Confirmation".

Step 4: Building the Board Feature

Let's build the core feature of Trello - the board where you can drag and drop tasks from one column to another.

I wrote a very simple and vague prompt into Claude Code. The reason this works is because Sonnet 4.6 is so advanced that it doesn't need hyper-specific prompts like other AI chatbots. It has an underlying understanding of everything going on in the project - making it the perfect model if you don't have the time and energy to write down every detail.

The result? Sonnet 4.6 replaced the entire homepage with a boards section. Since there's no board yet, it lets users know they can create one to get started. This is very smart from Sonnet 4.6 considering I didn't even tell it to do that.

The feature actually works - you can create new boards without any problems. But it's still far from what Trello is. We can't ship the app like this because the UI still needs work, and there's no guidance for new users.

Step 5: UI Customization & Polish

Trello is famous for its UI and ease of use. So I asked Claude Code to design the UI in a better way so that it's as easy - if not easier - to use than Trello.

In just a few minutes, Claude Code successfully built out a polished interface.

But it doesn't end there. People also love Trello because of how customizable it is - you can change the look of the entire app depending on your preference. We want our users to have the same flexibility.

I told Claude to add customizations and to persist settings globally - making sure any customization applies across the entire app, not only in some sections or tables.

After a few minutes, Claude Code was done. The app has every feature we wanted, and the UI is very polished. This is the perfect MVP for our mobile app.

Step 6: Publishing to the App Store

Because we used mobileboilerplate.io, the EAS configuration is already done. Just go to the terminal and type:

eas build --platform ios

Claude Code manages the certificates and signings. You'll get a .ipa file which you can upload to App Store Connect and wait for Apple's approval.

[!TIP] Be aware that uploading to the App Store might be a little annoying because there's always a reason they will reject your app. Join our community if you need any help.

Bonus: Marketing Strategy

This is something very important that no one ever mentions. Most people don't even think about marketing when building their app - they get reminded of it when everything is done, and that's backwards thinking.

The distribution and marketing strategy should be baked into the product itself. Here's exactly how I'd do it with the app we just cloned.

Step 1: Reverse Engineer Where Your Users Gather

Since this is a productivity app, where do productivity enthusiasts hang out? Reddit - specifically:

These are communities with millions of members who are actively looking for better tools to organize their work.

Step 2: Provide Value First

Create a free Notion template - like a Kanban project management system - and share it in these communities. It provides genuine value, and people will use it.

Inside that template, include a simple line like: "Want this on your phone with drag-and-drop, offline sync, and custom themes? Download Flowzone."

That's the best funnel to start with because it costs nothing, and there's huge opportunity for organic growth.

Step 3: Scale the Strategy

You can do the same thing on Gumroad - post a free productivity toolkit like a Kanban cheat sheet, a project planning framework, or a weekly review template, and funnel users from there into the app.

You can do this everywhere - Twitter/X, LinkedIn, and more. But the strategy is always the same: don't sell the app, sell the system and the need. The app is just the best way to use the system.

Final Thoughts

We started with an idea, built an app in less than 30 minutes, figured out how to publish it to the App Store, and even decided on a marketing strategy to get our first users and grow the app.

Sonnet 4.6 proved itself as the go-to model for fast, high-quality mobile app development. Combined with Opus 4.6 for architecture and planning, you have a powerhouse duo that makes building production-ready apps accessible to everyone.

Ready to start building?

Happy building!