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Personal Trainer – Lift, share plans, and rank with friends

Personal Trainer – Lift, share plans, and rank with friends

by erwanalliaume·May 12, 2026·6 points·0 comments

AI Analysis

●●SolidCozySolve My Problem

Offline-first gym tracker that settles dad-vs-son lifting debates without subscription walls.

Strengths
  • User-scoped Zustand stores via AsyncStorage key prefixes enable clean multi-account switching
  • Progressive overload suggestions rounded to standard plate increments shows real gym knowledge
  • One-time unlock model for premium features respects users instead of recurring subscription traps
Weaknesses
  • Friend leaderboard via code sharing feels limited compared to established social fitness apps
  • No mention of Apple Health or Google Fit integration, which most serious lifters expect
Category
Target Audience

Gym-goers who want privacy-focused tracking without subscriptions

Similar To

Hevy · Strong · Fitbod

Post Description

Hi HN, I'm an indie dev who built this to settle a long-running argument with my teenage son about who lifts more at the gym. I wanted a workout tracker to kept our data side-by-side on a leaderboard, and let us swap training plans without texting screenshots back and forth. Nothing I tried did all three without a subscription wall, so I wrote my own.

Most of the app is free, it covers the full workout experience and progress tracking with 80+ exercises. The one-time purchase unlocks multiple plans, custom movements, and the social/sharing features, mainly to pay for the infra.

The mobile app is React Native via Expo with Expo Router, NativeWind for styling, Zustand for state (every store is user-scoped via an AsyncStorage key prefix so account switches do a clean rehydrate, good way to have several using using the same app), Reanimated for animations, and react-i18next across six locales. The core workout loop is fully offline, and a Firebase layer sits on top for optional cross-device sync and the social features. Backend is a small workspace of Firebase Cloud Functions v2 that handle cross-user fan-out (friend requests, shared plans, shared movements) with rate limiting and anti-spam in Firestore triggers.

Published a few weeks ago, I can proudly but surprisingly see the daily usage increasing.

This is my first mobile app since a while (was doing some 10+y ago), keen for any feedback since it gave me the excitement of building some more.

Android only for now, iOS to be published soon.

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Solve My ProblemShip It
mihaibundea
103mo ago