AI Health App Bundle — CalmAI + NourishAI + ChefAI | 3 Flutter Full Apps

Three production-ready Flutter source-code apps in one purchase: CalmAI (mental health companion), NourishAI (AI calorie & nutrition tracker) and ChefAI (AI recipe generator & meal planner). Each is a standalone product with its own Firebase project, its own design system and its own store listing — reskin one, or ship all three.

Every app shares the same architecture — Flutter, Riverpod, GoRouter, Firebase Auth and Firestore, a Cloud Functions AI backend, dual AI providers (OpenAI or Gemini, switchable without an app update), RevenueCat subscriptions and AdMob — so learning one means you already know the other two. The bundle ships with a single unified documentation site that sets up the shared parts once, then covers what differs per app.

Your AI key never ships in the app

All three apps call OpenAI or Gemini through their own authenticated Firebase Cloud Function. Your provider key lives in Cloud Functions secrets — never in the source, never in Remote Config, never in an APK or IPA. Decompiling a release build yields nothing worth having.

• ✅ Key stays server-side — Google Secret Manager, injected into the function at runtime
• ✅ Authenticated calls only — an unauthenticated request is rejected before a single token is spent, so the endpoint is not an open proxy to your paid account
• ✅ Server-enforced daily caps — the counter lives in Firestore and the shipped security rules make it read-only to clients, so a modified app cannot reset it
• ✅ Prompts live on the server — the client sends structured parameters, never a prompt string, and every value is bounded before it reaches the model
• ✅ Firestore rules and indexes included for all three apps, written against their real collection layouts

This needs the Firebase Blaze (pay-as-you-go) plan, which is what Cloud Functions require. Blaze still includes the free tier.

Third-party services — you pay for these, not us

You are buying source code. You are not buying the services it runs on. Every external account these apps connect to is opened in your name, billed to your payment method and governed by that provider’s terms. Item support covers the code; it does not cover, subsidise or refund third-party charges.

• OpenAI or Google Gemini — billed per token on every request your users make. This is the cost that grows with your user base. Set a hard spending cap in your provider dashboard before launch.
• Firebase (Auth, Firestore, Remote Config, Hosting) — free within the Spark quota, then pay-as-you-go on Blaze.
• Firebase Cloud Functions — the Blaze plan is required; Functions cannot be deployed on the free Spark plan. There is a large free invocation tier above that.
• RevenueCat — free below their monthly tracked-revenue threshold, then a percentage of tracked revenue. Optional.
• Google AdMob — free; AdMob pays you. Optional.
• Apple Developer Program ($99/year) and Google Play Console ($25 one-off) for store distribution.