Underpriced App went live on Google Play - Profit Checker for Resellers
Hey IH! 👋
After months of building, I finally shipped the Android version of Underpriced and wanted to share the journey.
The problem:
I've been into reselling/flipping as a side hustle. The hardest part isn't finding items - it's quickly evaluating whether something is worth buying. You're standing in a thrift store, holding some vintage gadget, and you need to decide in 30 seconds if it's worth $5 or $500.
The solution:
Underpriced uses AI (Gemini) to analyze product photos and cross-references real sold data from eBay, Mercari, etc. to give instant pricing estimates and flip recommendations.
Tech stack:
- React + Vite frontend
- Vercel serverless functions for API
- Firebase for auth/data
- Capacitor for the Android wrapper
- Gemini API for image analysis
- eBay API for comp data
What I learned:
- Capacitor made the web → Android transition surprisingly smooth
- AI costs add up fast - had to implement smart caching and credit systems
- The reselling community is incredibly engaged and gives great feedback
Current state:
- Web app has been live since November 2025
- Android just launched this week
- Building toward profitability with a credit-based model
I'd genuinely love feedback from this community:
- How's the value prop sound?
- Any suggestions on the pricing/credit model for AI-based tools?
- What would make you actually use something like this?
Play Store: https://play.google.com/store/apps/details?id=com.underpriced.app
Thanks for reading! Happy to answer any questions about the build.
This actually looks like a helpful item scanner for resellers. Pretty much a google lens but fine tuned for flipping! Good luck with your journey!