Fit Flexed - Complete AI Fitness Platform | Flutter + NestJS Full-Stack

Fit Flexed - Complete AI Fitness Platform

A complete, production-ready fitness SaaS platform built with Flutter, NestJS, and React. Combines 52 fitness tools, AI-powered coaching, wearable integration, workout tracking, and subscription monetization — available on iOS, Android, and Web.

🚀 Key Features

🧮 52 Fitness Tools

• Calculators (15) — BMI, BMR, TDEE, 1RM, Body Fat %, Macro, Protein, Water Intake, Heart Rate Zones, VO2 Max & more

• Running & Cardio (8) — Pace, Race Time Predictor, Interval Timer, Split Timer, Calories Burned, Treadmill Converter

• Strength & Lifting (10) — Rep Max, Plate Calculator, Progressive Overload, Volume, Rest Timer, RPE, Periodization Planner

• Swimming & Cycling (6) — Swim Pace, FTP Power, Cycling Calories, Bike Fit, Triathlon Pace

• Nutrition & Diet (6) — Meal Planner, Food Log, Recipe Nutrition, Intermittent Fasting Timer, Supplement Tracker

• Body & Planning (7) — Measurement Tracker, Progress Photos, Weight Tracker, Workout Planner, PR Tracker

🤖 AI-Powered Features

• AI Workout Generator — generates workouts based on goals, equipment, duration, and difficulty

• AI Form Analyzer — video upload for real-time form feedback with scores and corrections

• AI Fitness Coach — 24/7 multi-turn chat for workout modifications, motivation, and recovery

• AI Nutrition Advisor — meal suggestions, food swaps, recipe modifications

• AI Progress Insights — plateau detection, deload suggestions, goal predictions

🏋️ Workout System

• Pre-built workout templates by type and difficulty

• Real-time active workout logging — sets, reps, weight, RPE

• Rest timer with notifications between sets

• Multi-week periodized training programs

• Exercise library with video demos, muscle groups, and equipment filters

• Workout history and personal records

🥗 Nutrition Tracking

• Food database with macro data

• Meal logging — breakfast, lunch, dinner, snacks

• Daily macro tracking — protein, carbs, fat, fiber, sugar, sodium

• Customizable nutrition goals

⌚ Wearable Integration

• Apple Health sync · Google Fit sync · Fitbit integration

• Synced data: activities, heart rate, sleep

📊 Progress & Social

• Progress photos with side-by-side comparison

• Personal record tracking, workout streaks, analytics charts

• Achievement badges and gamification

• Follow system, activity feed, community challenges with leaderboards

⚙️ More Features

• Guided Onboarding — personalization flow with fitness level, goals, and schedule

• Push Notifications — FCM + local notifications for workouts, nutrition, achievements

• Offline Mode — Hive local storage with auto-sync

• PWA Support — Progressive Web App with service worker

• Responsive — bottom nav (mobile) / NavigationRail (tablet/desktop)

• Multi-Language — intl package support

• Admin Dashboard — user management, subscription monitoring, stats

🛠️ Tech Stack

📱 Mobile App (Flutter)

• Flutter 3.x / Dart 3.0+ — iOS, Android & Web (PWA)

• State management: Riverpod · Navigation: GoRouter

• Charts: fl_chart · Offline: Hive · Secure storage: flutter_secure_storage

• Auth: Google Sign-In, Apple Sign-In · Notifications: Firebase FCM

• Payments: in_app_purchase (Apple StoreKit + Google Play Billing)

⚙️ Backend (NestJS)

• NestJS 11 (TypeScript) — 20 modules, 40+ DB tables

• Database: PostgreSQL 16 · Cache: Redis · Job queue: BullMQ

• AI: OpenRouter (GPT-4o-mini, Claude, GPT-4)

• Payments: Stripe + Apple IAP + Google Play Billing

• Storage: AWS S3 · Email: AWS SES · CI/CD: GitHub Actions

🌐 Landing Page

• React 19 + Vite + Tailwind CSS

• Privacy, Terms, Cookie Policy, Data Deletion pages

• Auto-deployed via GitHub Actions

💳 Subscription Plans

• Free — 15 tools, 3 workout templates, 7-day history

• Pro — $6.99/mo — All 52 tools, unlimited templates & history, 10 AI workouts/month

• Pro+ — $14.99/mo — Everything + unlimited AI coach, form analyzer, full wearable sync

• Yearly plans · Lifetime Elite tier · 7-day free trial

• Stripe + Apple IAP + Google Play Billing + webhook lifecycle handling

📦 What's Included

• 📱 Full Flutter source code — iOS, Android & Web

• ⚙️ NestJS backend — 20 modules, PostgreSQL migrations

• 🌐 React 19 + Vite + Tailwind CSS landing page

• 📋 Environment config templates (.env.sample)

• 📖 Swagger API docs (auto-generated at /api)

• 🔄 GitHub Actions CI/CD workflows

✅ Requirements

• Flutter 3.x / Dart 3.0+ · Android Studio / Xcode

• Node.js 18+ · PostgreSQL 16 · Redis

• AWS account (S3 + SES) · Firebase project · OpenRouter API key

💪 52 tools. 5 AI systems. Wearable sync.  |  📊 20 API modules · 40+ DB tables · iOS + Android + Web