Ever had an app idea while riding the bus? Instead of waiting to get home, I built the whole thing—from my phone. No laptop. No setup. Just Replit, Expo, and a few smart tools. Here's how it went, and what you can learn from it.
Tools That Made This Possible
- Replit app - A full browser-based IDE that runs on mobile
- Expo - For building and previewing React Native apps
- BrainDumper.ai - My free tool to turn rough ideas into structured app briefs
- Deepseek - AI API
- Windsurf - For App Store deployment (used only at the end)
The Exact Workflow I Followed
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Install and open Replit on your phone
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Use BrainDumper.ai to transform your idea into a clear project brief
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Remix the Expo/Replit starter template
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Run the project by hitting Play, then open the Console to preview live
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Set a custom system prompt in the Replit Assistant:
This is an Expo project for building React Native apps. Frame your responses accordingly.
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Paste your BrainDumper context into the chat and start building
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Debug by copying error messages into Assistant to get instant fixes
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Connect Deepseek API to replace placeholder data with real analysis
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Prompt Replit to improve the UI with better formatting and polish
Publishing to the App Store: Did It Work?
I attempted to run EAS Publish Preview for iOS directly from my phone... But the process failed due to mobile limitations.
So I moved to desktop for the final deployment:
- Downloaded the Replit project as a ZIP
- Opened it in Windsurf (AI IDE)
- Ran npx testflight for TestFlight deployment
- Used Cascade AI to fix errors and config issues
- Connected my Apple Developer account and uploaded to App Store Connect
Final Takeaways
What Worked Well:
- I built a real mobile app MVP entirely on my phone
- No local setup or installs needed
- Replit's Assistant + templates accelerated development
- Deepseek added working AI logic to the app
What Didn't Work:
- Publishing directly from mobile was clunky and unreliable
- A few bugs and edge cases required desktop-level debugging
🤔 Should You Try This?
If you want to quickly prototype mobile apps or test ideas on the go, this workflow is amazing. You can go from nothing → MVP in under an hour, without a laptop.
Pro Tip: If you're planning to publish to the App Store or handle backend logic, you'll likely need to finish on a desktop. But for rapid prototyping and initial development, this mobile-first approach is surprisingly effective!