Designing, building, and growing a solo iOS app to 3,500 users

Collectors had no good option: spreadsheets were too clunky, marketplaces too complex.

Card collecting is a deeply personal hobby. Collectors want to track what they own, understand its value, and share their finds with a community that gets it. But the tools available forced a choice between two bad options: manual spreadsheets with no visual appeal, or bloated marketplace apps designed for selling, not collecting.

• Spreadsheets required too much manual effort and had no visual payoff
• Marketplace apps were cluttered with selling features irrelevant to casual collectors
• Nothing existed that let users scan, track, and share quickly, without noise

That gap became the opportunity. Collectors needed something fast, intuitive, and built around the joy of the hobby rather than the transaction around it.

Growth was never an afterthought. It was designed into every feature from the start.

The reason I started Binder was to push my skills beyond craft and into distribution. That meant every design decision carried two questions: does this serve the user, and does this create a reason to share? Three principles shaped every call made along the way.

Three design decisions did most of the heavy lifting: onboarding, the share loop, and UI credibility.

The share loop

Every scanned card could be instantly turned into a shareable image optimised for TikTok, Instagram, and Discord, complete with player name, year, and set details. This created an organic distribution loop: users shared their collections, followers asked "what app is that?", and new downloads followed. Collectors love to show off their finds. The goal was to make Binder the tool that made that bragging look good.

UI built for credibility

Collectors trust polish. Every visual choice supported shareability: layouts framed cards beautifully, typography made data legible at a glance, and motion feedback made scanning feel premium. By nature, a collector who values the aesthetic of their physical cards will quickly dismiss an app that doesn't match that standard. Clean UI wasn't vanity; it was a trust signal.

Monetisation was treated as a design challenge: the goal was to give so much value that paying felt like a steal.

With low running costs, I could afford to be generous. Binder adopted a free-core, premium-upgrade model that kept free users fully functional while giving power users something genuinely worth paying for.

The model aligned incentives cleanly: free users drive growth through sharing, subscribers fund sustainability through upgrades, and both experiences feel generous rather than gated.

Paywall optimisation

The paywall went through several rounds of changes: real user testimonials became the first thing people see, the feature set moved just below the fold to invite a scroll, the button copy became action-led, and a promise to remind people before their trial ends gave them the confidence to start one.

250,000 weekly views across Instagram and TikTok. No paid ads, just content that felt native to the hobby.

Binder's growth came almost entirely from social content. Rather than paid acquisition, the strategy was to build genuine interest through a mix of broad sports content that appealed to collectors generally, and product-focused videos that showed Binder in use. The balance mattered: the brand needed to feel native to the hobby, not like a startup trying to sell an app.

Each viral clip acted as a lightweight product demo, showing the scanning flow, the shareable card output, or the stats page in action, and led directly to downloads. Binder's visual design played a supporting role here too. It photographed well, felt credible on screen, and stood out in a fast-moving feed. The product's shareability wasn't accidental; it was designed in from the start.

App Store analytics from the growth period: impressions up 540%, page conversion at 30.9%, downloads up more than 40×.

Growth was half the goal. The other half was a reason to come back that didn't rely on streaks.

Binder was designed to be sticky in a natural way. The more cards users added, the more value they built into the platform. Each scan deepened the sense of ownership and made it harder to leave. The collection itself became the reason to stay.

To support that habit, Binder surfaced meaningful updates over time. Weekly notifications highlighted changes to a user's collection: new additions, completed sets, movement in stats. The Stats page amplified that feeling. Watching numbers climb gave users the same hit they'd get from sorting cards in real life, a positive loop between collecting and opening the app.

Good design doesn't stop at usability. When built with intention, it drives distribution, retention, and revenue.

Binder's 2.4% churn rate sits well below the 5–9% category average. That retention came from genuine value, habit, and trust, not artificial engagement loops.

Looking back, there are two things I'd do differently. I'd invest in data visibility and analytics earlier. Deeper behavioural understanding would have helped prioritise features faster and identify drop-off points before they became problems. And I'd back myself sooner; initially I moved slowly out of caution, but the positive feedback that came in early was a signal I should have leaned into harder.