Building a mobile app often feels intimidating – ideas, tech choices, data sources, Play Store rules. This blog documents how I went from a simple idea to a working Android app, step by step, using AI as a development partner.
The goal of this post is simple:
To show that anyone can build and launch a useful app today, even without a large team, paid APIs, or complex backend systems.
1. The Idea: A Simple Daily Calendar App
The inspiration came from popular Indian calendar apps like Nithra Calendar.
I asked myself:
- What is the bare minimum value people actually check every day?
- Can this work offline?
- Can elders and families use it easily?
The core idea became:
A daily utility app that shows:
- Date
- Sunrise & Sunset
- Good Time (Abhijit Muhurtham)
- Daily Horoscope
No login. No ads initially. No clutter.
2. MVP Thinking: Go Minimal, Go Correct
Instead of copying large calendar apps, I focused on an MVP (Minimum Viable Product).
MVP Scope
✔ Today’s date (auto-updating) ✔ Sunrise & sunset (calculated, not stored) ✔ Good time derived from sunrise/sunset ✔ Horoscope that changes daily ✔ English + Tamil support ✔ Fully offline
What I intentionally skipped
❌ Yearly Panchang tables ❌ Paid horoscope APIs ❌ Backend servers ❌ User accounts
This reduced:
- Cost
- Complexity
- Maintenance
3. Key Technical Decision: No Paid Data
One big question was:
Where does the daily data come from?
The solution
- Date → Device system date
- Sunrise & Sunset → Astronomical calculation using date + location
- Good Time → Midpoint between sunrise & sunset
- Horoscope → Deterministic daily rotation logic
This means:
- The app works in 2025, 2026, and beyond
- No API cost
- No server dependency
Everything updates automatically when the date changes.
4. Choosing the Tech Stack
I chose:
- React Native (Expo)
- TypeScript
- Single screen MVP architecture
Why?
- Faster iteration
- One codebase
- Easy Play Store build
- Strong AI assistance
I tested on:
- Web (fast debugging)
- Android phone (real device testing)
5. Development: One Step at a Time
The development process was deliberately slow and careful.
Key milestones
✔ App booted successfully ✔ Scrollable layout fixed ✔ Date rendered correctly ✔ Sunrise & sunset logic verified ✔ Good time visible ✔ Horoscope for all zodiac signs ✔ Language toggle (Tamil / English) ✔ Mobile testing done
Each issue was solved one by one — from layout bugs to build errors.
AI acted as:
- Debug partner
- Architect
- Reviewer
6. Smart Feature Addition: Date Navigation
A major usability improvement:
Let users change the date
Features added:
- Left/right arrows to move between days
- Calendar picker
- Single
selectedDatestate controlling the entire app
Result:
- Past and future dates work
- All data recalculates instantly
- Still offline
7. Build & Release Readiness
Before Play Store release, I confirmed:
✔ App updates data automatically every day ✔ No manual refresh needed ✔ Works without internet ✔ Privacy-friendly (no data collection) ✔ Play Store policy safe
A proper Play Store description was prepared with:
- Clear feature explanation
- No misleading claims
- Family-friendly language
8. What This Proves
This project proves that:
- You don’t need paid APIs to build useful apps
- You don’t need a backend for every product
- You don’t need a large team
- AI can guide real production work
What you do need:
- Clear thinking
- Small steps
- Willingness to test and fix
9. What’s Next (Optional)
Future ideas:
- Ads (carefully)
- Paid ad-free version
- Location-based sunrise
- Festival highlights
- Monthly calendar view
But the core app is already valuable.
Final Thoughts
If you have an app idea sitting in your head, start small.
Build the simplest version that:
- Works correctly
- Solves one problem
- Can be shipped
With AI as a guide, the barrier to building software has never been lower.
If I can go from idea → APK → Play Store, you can too.
Happy building 🚀
