How to Build Professional Apps for Just $20 a Month Using AI: The Complete Step-by-Step Workflow

What if I told you that for just $20 a month, you could revolutionize how you build apps—without needing years of coding experience? Thanks to the latest AI tools like Cursor and Claude Code, you can now turn simple English instructions into fully functional, professional apps that generate real revenue. The era where you needed teams of developers and months of work is over. Now, you can bring your app ideas to life in just weeks, all by yourself.

In this post, I’ll walk you through the exact workflow I use to build real apps using AI—covering everything from ideation to deployment. Whether you’re a complete beginner or a developer looking to speed up your workflow, this AI builder playbook will transform how you think about app creation.

Meet Sage: A Real Productivity App Built with AI

To showcase the power of this workflow, I built Sage, a productivity app designed to motivate you to complete your daily tasks. Sage isn’t a demo or mockup—it’s a fully working app where users can:

• Create accounts and securely log in
• Add daily tasks and assign point values based on importance
• Track progress via a dynamic progress bar that changes color based on points completed
• Earn achievements and visualize productivity streaks on a calendar

This gamified design makes daily task completion satisfying and addictive—the key to why productivity apps are so popular.

Step 1: Ideation — Define Your App Idea Clearly

Start by brainstorming your app idea with AI assistants like ChatGPT or Claude. The trick is to be as specific and direct as possible. For Sage, I told Claude I wanted an iOS productivity app incorporating gamification inspired by GitHub’s heat map concept used in habit trackers.

The AI helped generate ideas, suggest app names (like “Sage”), and even icon concepts. For instance, I used OpenAI’s image generation model to create a fitting app icon, bypassing the need for graphic designers.

Pro Tip: Keep refining your idea through natural conversations with AI until you arrive at a clear Minimum Viable Product (MVP) concept.

Step 2: Plan the MVP Structure

An MVP is the simplest version of your app that fulfills its core purpose. I asked Claude to draft the MVP structure, including pages and features like user login and a cover page. After some iteration to remove unnecessary elements, I finalized the app’s basic structure.

I organized this into a structure.md file inside a docs folder to serve as the blueprint for the next steps.

Pro Tip: Use Git to track changes throughout the project—even if you’re new to programming, AI coding agents can handle Git commands for you.

Step 3: Build the Initial Prototype in HTML

Ask your AI coding agent to build a prototype based on the MVP structure—using HTML is ideal here because it’s simple and easy for AI to generate.

The first prototype will have all components but might not look exactly how you want. Focus on perfecting the app’s structure at this stage—decide on buttons, widgets, progress bars, etc.—without worrying about colors or styles yet.

Iterate by giving the AI feedback and screenshots, refining the layout until the structure matches your vision.

Step 4: Design Your App with JSON Styling

Once the layout is solid, it’s time to make your app visually appealing. Instead of designing everything manually, you can:

• Find UI inspiration or take a screenshot of a design you like
• Use ChatGPT to generate a design.json file that describes colors, fonts, and styling based on your inspiration
• Apply the JSON to your HTML prototype to transform the look while preserving the layout

Important: Finalize your color scheme and design elements here. Avoid adding animations or complex UI behaviors yet—those come later.

Step 5: Convert Your Prototype Into a Real App

With a polished HTML prototype, the next step is converting it into a working app on your target platform. For Sage, I converted the HTML into an iOS app using SwiftUI.

By instructing Claude to generate conversion rules and using those in Cursor, the AI seamlessly transformed the HTML into native SwiftUI code. The UI components adapted to iOS conventions while maintaining the original design.

This method is flexible—you can convert HTML prototypes to virtually any framework with the right templates and AI guidance.

Step 6: Build the Backend and Database

A real app needs persistent data storage and secure user authentication. I integrated Sage with Supabase, a hosted backend platform that provides databases and authentication with minimal setup.

Thanks to Supabase’s new tools like their MCP server, I didn’t have to write SQL or configure servers manually. I simply instructed Cursor to integrate Supabase, and it:

• Created the database schema based on the app’s data needs
• Installed the Supabase SDK
• Implemented login and data storage functionality

This process took just 15 minutes—backend setup has never been faster or easier.

Step 7: Refine UI and Add Finishing Touches

While AI can get you most of the way, polishing the user interface takes time and iteration. Good UI involves animations, color changes, subtle effects, and responsive behaviors.

I switched to Claude Code for more complex UI tasks like adding animations and tweaking the calendar and settings pages. These refinements took several hours but made the app feel professional and satisfying to use.

Remember, there’s no single AI prompt that creates perfect UI. It requires adding small details and continuous improvements.

Bonus Tips

• Use ChatGPT to enhance app assets like icons—upload your basic icon and ask for improvements.
• Keep your Git commits organized at every stage to track progress and roll back if needed.
• Finalize your color palette early to avoid costly redesigns later.
• Iteration is key: plan for multiple rounds of UI improvements even after your app is functional.

Conclusion: The AI-Powered Future of App Development

Building professional apps no longer requires years of coding expertise or large teams. For just $20 a month, AI tools empower anyone to create real working apps—from ideation to deployment—with minimal manual coding.

By following this step-by-step workflow, you can:

• Brainstorm and refine app ideas with AI
• Quickly prototype and design using HTML and JSON
• Convert prototypes into native apps
• Seamlessly integrate backend and authentication
• Polish UI through iterative refinement

With patience and persistence, these AI-assisted apps can generate revenue and deliver real value to users.

If you found this guide helpful, consider subscribing to our channel for more AI app-building tutorials and resources. Happy building!

Ready to start your AI-powered app journey? Tools like Cursor and Claude Code await your ideas!