Comprehensive Fitness App Development - Full Stack

Title: Full-Stack Mobile Developer — Fitness App (Workouts, Meal Plans, Subscriptions, AI Chat, CRM)
Category: Technology & Programming → Mobile App Development
Type: Fixed price, milestone-based
Budget: $8,000–15,000 (negotiable based on proposal; see phases below)
Experience level: Expert
Project length: 3–5 months, potential for ongoing maintenance contract
Description:
We're building a fitness app for a client (a personal training business) and are looking for an experienced full-stack mobile developer or a small team to take it from spec to launch. Below is the full scope, split into phases so we can work milestone by milestone.
Platform & Tech:

iOS + Android (cross-platform preferred: Flutter or React Native — tell us which you'd use and why)
Backend: your recommendation (Node.js/Django/Supabase/Firebase are all fine — justify your choice)
We will provide branding (logo, colors) and content (exercise library, meal plan templates)

Phase 1 — Core App (MVP):

User registration/login (email + Google/Apple sign-in)
Onboarding questionnaire (goals, fitness level, dietary preferences, allergies)
Personalized workout plans: generated from the onboarding data using our rules/templates; users can log sets, reps, weights, and track progress with charts
Personalized meal plans: weekly plans based on calorie targets and dietary preferences, with swap options for individual meals
Push notifications (workout reminders, streaks)

Phase 2 — Monetization & Community:

Subscription model: free tier + monthly/annual premium via App Store / Google Play billing (and Stripe for web if feasible); premium unlocks full meal plans and advanced programs
Community chat: group channels + direct messages between users and coaches; basic moderation tools (report, mute, ban)

Phase 3 — AI Assistant & CRM:

AI chat assistant: LLM-powered Q&A inside the app (fitness/nutrition questions, app navigation help). We expect integration with an API such as OpenAI or Anthropic, with a system prompt limiting it to fitness topics and a clear disclaimer (not medical advice). Include your approach to cost control (caching, rate limits per user).
CRM backend (admin panel): web dashboard for the client to manage users, view subscription status and revenue, send announcements/push campaigns, edit workout & meal templates, and view basic analytics (retention, DAU, churn)

Deliverables:

Source code in a private Git repo (full ownership transfers to us)
Deployed backend + published apps in both stores (we'll provide developer accounts)
Basic documentation (setup, architecture overview, how to edit templates)
30 days of post-launch bug fixing included