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  Presentation 1

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  Presentation 2

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  Home screen with collection data

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  Scan Screen

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  Card Detail Screen

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  Edition track screen

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  Item search screen

About the Project

We built this application as a team of two: myself and my friend and co-founder, Alvyn Yang.
We’ve been collecting Pokémon and Yu-Gi-Oh! cards for about a year, and as my collection grew, I realized I needed a proper way to manage and track it. That’s where the idea of this project came from.

Alvyn and I had already worked together on a previous app (Subflow, released last year), so when I pitched the concept, he immediately said yes. To validate the idea, I reached out to my small Build in Public community on X (Twitter). The feedback was overwhelmingly positive, which gave us the confidence to get started.

Just two days later, we came across a post from RevenueCat about the Shipathon. We decided to take on the challenge and committed to shipping this ambitious project in only two months. Alvyn took the backend, and I focused on the frontend.

Challenges We Faced

• Tight deadline: We had never worked on a project of this scale with such a short timeline. To make things harder, both of us were away for one week on vacation, which impacted our schedule.
  
• AdMob integration: It was our first time working with AdMob. We had to carefully balance ads so they weren’t intrusive for users, but still visible enough to encourage RevenueCat subscriptions.
  
• AI scanning feature: The most complex functionality was implementing AI-powered scanning with Gemini Flash 2.5 and connecting it to real-time pricing data from the two major European TCG marketplaces: CardMarket and eBay.
  
• Community-driven development: We frequently adapted features based on feedback from our X community, which meant iterating fast and sometimes changing direction mid-development.
  

What We Learned

• How to build under extreme time pressure while keeping quality in mind.
  
• The importance of user-centric design, especially when balancing ads and subscriptions.
  
• How to integrate advanced tools like AI scanning and third-party marketplaces into a seamless user experience.
  
• The value of building in public: our community’s feedback pushed us forward and shaped the product.
  

Future of the App

• Scan performance improvements: Enhance the accuracy and speed of AI-powered card recognition.
  
• Social features: Allow users to view and like their friends’ collections, adding a community layer.
  
• US market: Have the USA TCG marketplace leader TCG PLAYER to our data bases to attack a new market.
• More TCGs: Expand beyond Pokémon / Magic / Yu-Gi-Oh! / One Piece and Lorcana by integrating additional trading card games (like Digimon TCG for exemple)
• TikTok presence: Launch a TikTok account to promote the app and grow visibility through social media.
  

Reflection

These two months were intense but incredibly rewarding. We battled through challenges, learned a ton, and leaned on each other and our community for support. In the end, we’re proud of the product we’ve delivered—and even prouder of the journey that got us there.

Built With

• admob
• expo.io
• javascript
• node.js
• prisma
• railway
• react-native
• supabase