From words to action: my journey to create an app with AI

From concept to requirements - how I'm using AI to build a real-world application focused on mental wellbeing

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Hey there 👋

Do you remember these words from my last newsletter?

Next week, I’ll put this theory into practice. I’ll start building a mobile application using these modern AI tools step by step. I’ll show you firsthand how these advancements translate into real development.

And look, a week has passed! 😊 A promise is a debt, they say, and now it’s time to show you how I approached this.

When I was thinking about what to share with you, the following thoughts were running through my mind:

At first, I thought: “I’ll simply build a template application and show the steps and tools.” But then I asked myself: Why not create something that has actual value? Something that could change someone’s life for the better?

WHAT

This led me to a profound question I asked myself:

What would be the most useful application in the world?

Of course, we’re going for the hardest possible challenge. 😄

But I think it’s doable:

Think about it for a moment. What if we look at life as a game? What would “winning” this game mean?

Probably something different for each of us… We all seek that shiny thing, what advertisements sell us as the “key to happiness.” But deep down, we all know that’s not real happiness.

So I asked myself that classic question that always puts things in perspective:

When I’m 80 years old, what will I regret?

This deep reflection led me to the idea of a habits app that would help you become the person you want to be. Or even better, help you discover who you already are.

WHY (More important than WHAT!!)

The more I thought about habits that positively impact my life, the more I questioned their deeper meaning:

And suddenly it dawned on me: before every action in real life, there’s a thought. Thoughts shape our emotions, and emotions shape our actions. What we regularly think, we become.

At that moment, I laughed. Of course! I need to make an app for thoughts! 😃

No joke:

Have you ever experienced that moment of clarity when your thoughts are directed, focused, and guiding you in the right direction? That feeling of inner power and harmony? But before we can start directing our thoughts, we must first notice them, become aware of them.

Meditation is an excellent training for this, but at the same time, my solution needs to be accessible to everyone - meditation probably isn’t right for the first step, though I definitely see it in the app in the future. Right now, I need something that works in our fast-paced lives.

With this clarity, I was much closer to the concept of my application. 💪

The name?

“Mind Fitness Now”: exercise for the mind, here and now.

How I Built Product Requirements

What Are Product Requirements and Why They Matter

Product requirements are the heart of every successful product. They’re like a house blueprint - without one, you’ll build randomly and end up with something that might not serve its purpose. Good requirements clearly define what the product must achieve, who it’s for, and which problems it solves. They’re a compass that guides you through all development phases and helps you make the right decisions when you reach crossroads.

My Requirements Design Process

Here I decided to use an AI approach that I’ve been utilizing lately. The process was as follows:

  1. Voice conversations with GPT-4o during walks While walking and letting my thoughts flow, I had conversations via headphones with GPT-4o about what I wanted to build. This freedom of movement and speech unleashed my creativity in a way that typing never achieves. At the end, I asked for a summary that captured the essence of our conversation.
  2. Diving deeper with GPT-o3 (the so-called reasoning model) I then transferred these ideas into a more structured dialogue:
    • Together we analyzed the pros and cons of different approaches
    • We researched similar products on the market and their shortcomings
    • We prepared a PRD (Product Requirements Document) with clear requirements
  3. “Hiring” another expert Then I did something I warmly recommend to you: I sought another pair of eyes. With Gemini 2.5 Pro, I reviewed all requirements again, looking for blind spots and possible improvements.
  4. Iteration and improvements Based on all the feedback, I improved the PRD multiple times until I was confident I had solid foundations.
  5. Defining main user flows Only then did I start planning key interactions in the application.
  6. Documenting everything in Readme files I documented everything in clear files that serve as development guidelines.

During the process, I compared the effectiveness of different large language models for this work: Claude 3.7, GPT-o3, and Gemini 2.5 Pro. I must admit that Gemini surprised me the most with the quality of its suggestions for this specific case.

Few chat examples:

GPT-4o

GPT-4o

Gemini 2.5 Pro

Above is one really miniature snippet (start) of very long conversations.

Why so long?

You’re quicker to fix a text than the app later. 😉

What’s Next?

So now you have insight into my thought process from idea to structured requirements. I hope this approach will benefit you in designing your projects. Sometimes the path to a good product is more winding than we might think, but it’s precisely in these curves that the greatest ideas hide.

In the next newsletter, a more practical part awaits you: how I set up the development environment and tools to make programming with AI maximally effective. I promise it will be full of concrete instructions that you can immediately put to use.

Until then, may your thoughts guide you in the right direction! 🚀
Primoz