🎾 I built and shipped a padel app. Solo. From idea to the App Store.

This is SMASH — and here's the whole story, the stack, and who it's for.

The problem I lived

I play padel. And like everyone who plays, I was organizing matches across four different WhatsApp groups, arguing about who won, with no real ranking and no easy way to run a club league. Clubs were managing tournaments in Excel. The fastest-growing sport in the world had no home on your phone.

So I built one.

What SMASH is

An iOS app that turns padel into a social, competitive experience:

• Organize matches and track results • A real ELO ranking, by city and by level — win, you climb; lose, you drop • Leagues & tournaments where the app auto-generates the bracket and standings • Matchmaking ("I want to play") that fills your game with players nearby • A short-video feed for your best padel moments • Push notifications that bring you back ("you've been challenged", "you moved up to #3 in your city")

How I built it (the stack)

Frontend: • Flutter / Dart — one codebase, iOS-first • Riverpod for state management • Custom UI (Material + Cupertino, glass effects), fully localized (ES/EN) • Video pipeline: playback, caching, compression, thumbnails

Backend — 100% serverless on Firebase: • Cloud Firestore — real-time database for users, matches, squads, leagues, tournaments • Cloud Functions (2nd gen, Node 24) — server-side ELO calculation, a push-notification fan-out system, and city-based matchmaking • Firebase Auth (Google + Apple Sign In) • Firebase Cloud Messaging for push (APNs) • Firebase Storage for media • Security rules + composite indexes

Monetization: • RevenueCat + StoreKit 2 — subscriptions, freemium model (play for free, organize as Pro)

Systems I built from scratch: • The ELO algorithm (K=32, team-average) for fair competitive ranking • A round-robin generator for tournaments • A viral invite loop (a padel match needs 4 players → every game created is an invitation)

Who it's for

Primary — padel players, from casual to competitive: people who play weekly and want to organize better, measure their real level, and compete. Starting in Spain, expanding to the padel hotspots: Italy, Sweden, Germany, the US (Miami, California), and Australia.

Secondary (B2B) — padel clubs: run official leagues and tournaments with zero paperwork, and add a booking link so players find and book courts. Recurring, defensible revenue.

What I actually learned

Shipping alone means being the product manager, designer, Flutter dev, backend engineer, growth marketer and App Store submitter — often in the same afternoon. I learned that features don't make a startup; loops do — a retention loop (notifications), a growth loop (invites), and a business model that scales. I learned that "global from day one" is a trap: 500 real users in one city beats 0 scattered worldwide.

And I learned that the last 10% — App Store review, push certificates, subscription approvals — is where most side projects quietly die. So I pushed through it.

SMASH is live on the App Store now, and I'm building it in the open with the players who use it.

If you play padel, run a club, or just like watching a product get built from zero — I'd love your feedback.