How I Built a Fully Functional Android App with AI in Just 5 Hours (No, Seriously!)

In recent months, AI has been changing the way we think about work, but it wasn't until I got hands-on that I truly understood just how powerful AI has become for developers like me.

I've always been a bit skeptical about the idea of AI replacing jobs in the short term. I figured it would take another 5 to 10 years before we saw real disruption. But after what happened to me just a few days ago, I can confidently say—AI is ready now. Almost.

The Experiment: Can AI Build My Android App?

Two days ago, out of sheer curiosity (and boredom), I decided to push AI to its limits. I've worked as a native Android developer for years, so I figured, why not let AI step into my world? I wanted to see if AI could help me build a complete Android app using Jetpack Compose and Koin—two tools I often rely on.

But here's the twist: rather than sticking with Android Studio plugins or Copilot, I decided to go full throttle with Cursor AI—a VS Code-based AI agent that can access your project directory.

The result? A fully functional, animated, and beautifully designed Alarm Clock app completed in under 5 hours!

The Setup: Giving AI the Right Tools & Context

I joined a Discord campus group run by Android YouTuber Philipp Lackner, where we often share app challenges. I chose one of the past challenges: an Alarm Clock app with a full set of specs and Figma designs.

video demo

Here's where it gets interesting:

I opened Cursor AI and loaded my fresh Android Studio project directory.
Then, I uploaded the project's documentation and Figma screenshots to Claude AI (Claude 3.7).
I asked Claude to generate a detailed project description that Cursor AI could follow end-to-end.

Here's the exact prompt I used:

"I am trying to create this app.
I will do the extended version.
I am using Jetpack Compose and an AI agent Cursor.
I need you to write a strong description so I can give it to the AI agent to know what we are building.
Describe everything in detail as it will use only your description to reproduce the whole project."

Claude responded with a crystal-clear project outline, which I saved as app_description.txt for future prompts.

Planning the Roadmap with AI (AI Helping AI!)

One thing I've learned is that AI sometimes loses context on large projects. So, I had another lightbulb moment—why not let Claude map out the project workflow too?

I prompted:

"Suggest how we proceed to build this.
I think we need to set up Koin, etc. Suggest a step-by-step breakdown to build the complete project so that I can prompt it step by step."

Boom! It returned a clear roadmap broken into 11 steps, including dependency setup, database creation, repository implementation, navigation, UI, and more.

Building the App with Cursor AI in 13 Conversations

With my project roadmap in hand, I started feeding Cursor AI each step in batches.

Here's how I tackled it:

Step 1: I asked Cursor to handle project setup, Gradle dependencies, and Koin configuration.
Pro Tip: Be clear about your preferences (e.g., using a libs.versions.toml file instead of inline Gradle declarations). AI will usually opt for "what works," not necessarily "best practices."
Steps 2-4: I combined tasks like setting up the Room database, creating data models, repositories, and building the navigation and theme into a single prompt to boost efficiency.

Here's an example of how I prompted it:

--- specifications are in @app_description.txt
I just finished step one.
Now, let's do steps 2, 3, and 4:
- Data models, Room database, and repositories
- Domain layer with use cases and alarm scheduling logic
- Navigation setup and theme creation ---

I repeated this pattern for the remaining steps.

Handling Bugs & Errors (AI is Good, but Not Perfect)

While AI did an outstanding job, there was one stubborn bug it couldn't solve on its own—an issue related to reassigning the flags variable in an Intent inside my AlarmService.

No biggie. I reviewed the code, spotted the issue, and fed the solution back to AI like this:

"You can see that the issue comes from here:
val fullScreenIntent = Intent(this@AlarmService, MainActivity::class.java).apply { putExtra(ALARM_ID, alarmId) flags = Intent.FLAG_ACTIVITY_NEW_TASK }But it's clashing with onStartCommand. Please fix."

After resolving that manually, the app built successfully. From there, it was mostly smooth sailing—occasional bugs popped up, but Cursor AI fixed them each time by simply pasting the Logcat error logs.

Polishing the UI/UX to First-Class Standards

While the app worked fine, the design felt... average. So, I challenged the AI:

"My app functions well, but the UI and UX are mediocre. Let's upgrade to world-class standards. It should be beautiful and intuitive."

I was genuinely blown away by what Cursor AI produced—fluid animations, better spacing, and a much more polished look.

I tested core functionalities like setting alarms, notifications, and scheduling, and everything worked as expected.

See It for Yourself (Open Source)

The full project is open source! You can check out the repository here:
➡️ GitHub - SnoozeAlarm App

Key Takeaways: What I Learned from Building an Android App with AI

🧠 1. AI is ready—but YOU need to steer it

AI can handle 80% of the heavy lifting, but you need to provide structure, preferences, and guidance. Understanding Android and software development principles is still crucial to getting the most out of AI.

🛠 2. Give clear prompts, but don't overthink it

Yes, prompt engineering matters, but AI understands casual instructions too. Avoid making tasks too big or too small—balance is key.

🔄 3. AI isn't afraid of bugs

Whenever I faced build errors or crashes, I pasted the error messages into AI, and it handled most of them like a pro.

🎨 4. Don't settle on the first draft of UI

AI can easily improve your designs. Just ask! The more descriptive you are about how you want your UI to "feel," the better the results.

Final Thoughts: Will AI Replace Developers?

After this experiment, my mindset has shifted. AI won't completely replace developers today, but it supercharges productivity. What took me 5 hours could've taken 5-10 days solo. Even a month in my case.

The bottom line: AI is no longer just a "coding assistant." It's now a capable teammate.

💡 Pro tip: If you're building Android apps with AI, make sure to:

Specify your preferred architecture (MVVM, Clean Architecture, etc.)
Define your DI tools (e.g., Koin, Hilt if you care about these details)
Decide early on where and how you want dependencies managed (Gradle vs. libs.versions.toml)
Continuously check the codebase for best practices

Have you tried building a complete app with AI? Let me know in the comments!

I Created a Trello Clone (Karaban Style Board) - Frontend and Backend

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