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markdown# I Shipped a Python Learning App with Zero Money — Here's Every Free Tool I Used
A 19-year-old developer from Bangladesh. No funding. No team. Just free tools, free APIs, and stubbornness.
I'm Simanta. I built Codino — a Python learning app with an offline IDE, AI tutor, Jupyter-style notebook, gamification, and data science library support — and published it on the Google Play Store.
My total budget: $0.
This is the complete breakdown of every single tool I used, why I chose it, and exactly how it fits into the app. No fluff.
The Stack at a Glance
| What I needed | Free tool I used |
|---|---|
| Code editor with syntax highlight | Sora Editor |
| Python in the browser/notebook | Pyodide + Skulpt |
| AI tutor with generous free tier | Google Gemini API |
| Extra AI fallback providers | Groq, OpenRouter |
| Backend (no-cost) | Supabase free tier |
| UI framework | Jetpack Compose |
| App distribution | Google Play Store |
1. Sora Editor — The Code Editor That Saved Me Months
Building a code editor from scratch for Android is a nightmare. Syntax highlighting, auto-indentation, bracket matching, line numbers — all of that is extremely hard to implement yourself.
Sora Editor is a free, open-source rich-code-editor library for Android. I plugged it directly into Jetpack Compose and got a fully working IDE in hours instead of months.
What it gave me for free:
- Syntax highlighting for Python (and other languages)
- Autocompletion support
- Smooth scrolling even on low-end Android devices
- A clean, dark-theme-friendly design
If you're building any kind of coding or text-heavy Android app, use Sora Editor. There is no reason to reinvent it.
GitHub: github.com/Rosemoe/sora-editor
2. Skulpt — Running Python Instantly in Lessons
For the lesson-based IDE (the basic code runner students use during lessons), I used Skulpt.
Skulpt is a JavaScript implementation of Python. It runs Python code entirely in the browser/WebView — no server, no internet, no waiting.
Why Skulpt over something heavier:
- Extremely lightweight
- Loads instantly inside a WebView
- Perfect for beginner-level Python (variables, loops, functions, conditionals)
- Zero cost, zero server calls
The limitation: it doesn't support advanced libraries like NumPy. But for the lesson environment, it's perfect.
3. Pyodide — Real Python for the Jupyter-Style Notebook
For Codino's notebook feature (the JupyterLab-style cell interface), I needed something more powerful — something that could actually run NumPy, Pandas, and Matplotlib.
That's where Pyodide comes in.
Pyodide is CPython compiled to WebAssembly. It runs real Python inside a browser. It supports 20+ scientific libraries including:
numpypandasmatplotlibscikit-learn
I embedded Pyodide inside an Android WebView and built the cell-based notebook UI on top of it using Jetpack Compose for the outer shell.
The result: a fully working, offline-capable data science notebook on Android — for free.
This is the feature that separates Codino from every other Python app on the Play Store. Most apps don't touch real libraries. I got them all for free through WebAssembly.
Website: pyodide.org
4. Google Gemini API — The Free AI Tutor
Every AI-powered learning app charges for the AI. Mimo charges. Sololearn charges. I didn't want to do that.
Google's Gemini API has a generous free tier — enough to give every Codino user real AI hints, full lesson explanations, and code understanding without paying anything.
How I use it inside Codino:
- AI hint button inside each lesson → calls Gemini
- AI explains quiz answers in markdown
- AI explains code written in the IDE
- Responses render as beautiful formatted markdown inside the app
The free tier limits are high enough that most users never hit them in a day of learning.
5. Groq — A Backup AI Provider That's Insanely Fast
Gemini is great, but having only one AI provider is risky. If it goes down or a user hits the daily limit, the AI feature breaks completely.
So I added Groq as a fallback.
Groq is a free AI inference API that runs open-source models (like LLaMA and Mixtral) at an almost unbelievable speed. It's the fastest AI API I've ever used.
My multi-provider strategy:
- Try Gemini first (best quality, generous free tier)
- Fall back to Groq if Gemini limit is hit (fast, free)
- Optionally add OpenRouter for additional model variety
The user never sees any of this. They just get a response. The system handles it silently in the background.
This is how you build AI reliability for zero dollars. Don't depend on one provider.
6. Supabase — Free Backend and Auth
User accounts, streaks, leaderboard data, XP progress — all of that needs a backend.
Supabase is an open-source Firebase alternative with a very generous free tier:
- 500 MB database
- Authentication built-in
- Realtime subscriptions
- REST and direct SDK support for Android
I used Supabase to store:
- User profile and progress data
- Streak history
- Leaderboard scores
- Daily AI quota tracking
It cost nothing.
7. Jetpack Compose — The UI That Looks Premium
The only way to make a free app feel premium is to make it look and animate beautifully.
Jetpack Compose is Google's modern Android UI toolkit. It's free, open-source, and very powerful for building smooth, animated UIs.
Everything you see in Codino — the dark UI, the smooth lesson transitions, the animated streak counter, the glowing leaderboard — was built purely with Compose and its animation APIs.
No paid UI libraries. No design assets I paid for.
8. Google Play Store — $25 One-Time Fee
This is the only money I spent.
The Google Play Store has a one-time developer registration fee of $25. After that, you can publish unlimited apps forever.
That $25 is the only real cost of building and shipping Codino.
The Honest Reality
Building with free tools is not the easy path. It comes with real challenges:
- Pyodide is heavy. The first load inside WebView can be slow. You need to manage loading states carefully.
- Free API tiers have limits. You have to build fallback logic, not just assume one provider works.
- Sora Editor needs configuration. It's not a plug-and-play drop-in. You'll spend time tuning it.
- Supabase free tier has row limits. You need to design your schema efficiently from day one.
But none of these problems cost money. They cost time. And time is the one resource a 19-year-old gap year developer has.
Final Thought
The biggest lie in software development is that you need money to build something real.
You don't.
You need Google, GitHub, patience, and a willingness to read documentation at 2am.
Codino is proof. A Python learning app with an offline IDE, AI tutor, Jupyter notebook, data science libraries, gamification, leaderboard, and free certificates — built by one person, from Bangladesh, with zero dollars.
If I can do it, so can you.
Codino is available on the Google Play Store. Search "Codino Learn Python" or click here.
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