NutriSync Mobile — Requirements beyond the Figma

Scope the Figma screens do not cover but the briefing commits to. Two families: (A) health & sport connectors, and (B) data rights + account lifecycle. Plus (C) the cross-cutting mobile capabilities those two imply. Grounded in the Developer Specification (§6 CAS, §13 Settings) and the business-case/deck roadmap (wearables strategy, M4→Y3).

Status as of July 2026. The visible app is now effectively 1:1 with the Figma prototype and fully wired to Supabase + CAS on both mobile and web. Of the "beyond-Figma" work below, two data-rights pieces are already built: in-app JSON export and delete account ship today in Settings → Data Privacy. The remaining items are the ones the Figma never showed and that are still open:

Wearable connectors (A) are documented only. They require a native development build — Expo Go cannot load the native HealthKit / Health Connect modules — so nothing here syncs until that build exists. Roadmap: 2028 (Epic E).
Full account erasure (B2) works in-app for the user's data, but wiping the underlying auth record needs a service-role Edge Function (the service_role key must never ship in the client). That function is pending.
Auth hardening (C) — 2FA and passkeys — is intentionally deferred.

A. Health, wearable & sport connectors

Status: documented, not built. Needs a native dev build (not Expo Go).

Why it matters to the product, not just "integrations": the CAS algorithm today is fed by manual logs — the morning mood/energy gate, Edit Period, and MovementLog (Dev Spec §6.1). Connectors let those same signals arrive automatically and objectively, which is exactly what the deck's "data moat" and "50% churn reduction for connected users" depend on. Each connector maps to a specific CAS component:

Source	Signals pulled	Feeds CAS component
Apple Health + Apple Watch (iWatch) — via HealthKit	HRV, resting HR, sleep, active energy, steps, workouts, wrist/skin temperature (Apple Watch Series 8+), blood oxygen, menstrual/cycle data, weight	Biomarkers (25) · Fitness (20) · Phase Confidence (skin-temp)
Android Health Connect / Google Fit	same categories on Android	same
Oura Ring	skin-temp trend, HRV readiness, sleep score	Biomarkers · Phase Confidence
Garmin / Fitbit / Whoop	workouts, HR, sleep, recovery	Fitness · Biomarkers
Strava	runs, rides, workouts (auto-fills MovementLog)	Fitness · Logging
CGM — Dexcom / Abbott Libre	glucose across the cycle	Biomarkers (future)

CAS component reference (see the Developer Spec §6): C1 Phase Confidence (15) · C2 Biomarkers (25) · C3 Nutrition (30) · C4 Fitness (20) · C5 Logging (10). Connectors primarily strengthen C1, C2, C4 and C5.

A0. The 8 platforms/devices to support (ranked)

Chosen by blending 2025 global market share (IDC / Statista) with health-data value for a cycle-nutrition app. Apple leads the wearable market (~28% share); Apple, Samsung, Xiaomi, Fitbit and Garmin together hold ~62%; Huawei is the #2 smartwatch vendor (25.5M units, 2025).

#	Platform / device	Why it's in the 8	How we connect
1	Apple Health / Apple Watch	Market leader (~28%). HealthKit is the iOS data hub; Apple Watch gives HRV, sleep & wrist temperature.	HealthKit (native)
2	Samsung Health / Galaxy Watch	Top-3 vendor; Galaxy Watch has skin-temp + built-in cycle tracking.	Health Connect + Samsung Health SDK
3	Google / Fitbit (Health Connect)	Fitbit (Google-owned) is top-5; Health Connect is the Android aggregation layer (replaces Google Fit).	Health Connect + Fitbit Web API
4	Garmin	Dominant in sport/endurance; rich HRV, sleep, Body Battery, women's-health tracking.	Garmin Health/Connect API (OAuth2)
5	Xiaomi (Mi Band / Mi Fitness)	Wristband volume leader — scale & affordability, very strong in Spain/Europe.	Health Connect / Mi Fitness
6	Huawei Health / Watch	#2 smartwatch vendor globally (25.5M units, 2025); strong in Europe & Asia.	Huawei Health Kit
7	Oura Ring	Smart-ring leader; gold-standard skin-temperature + cycle prediction — most femtech-relevant.	Oura API v2 (OAuth2 + webhook)
8	Strava	Leading sport/activity platform; auto-fills MovementLog with runs, rides & workouts.	Strava API (OAuth2 + webhook)

Honourable mentions: Whoop (recovery/strain) and CGMs (Dexcom / Abbott Libre) — added later per the deck's Y3 roadmap.

The native-build gatekeeper. Think of Expo Go as a shared demo phone with a fixed set of apps installed — it can run our JavaScript, but it can't install a new native library like HealthKit on demand. To talk to Apple Health, Health Connect, or a vendor SDK we must compile our own binary (a native dev build via EAS) that bundles those modules. That's why every connector below is blocked on the native build, regardless of API readiness.

A1. OS-native health (priority — MVP+, targeted after the native build lands)

iOS: Apple Health (HealthKit) — the primary iOS integration. Reads data the Apple Watch writes into Apple Health (HRV, sleep, skin temperature, workouts, blood oxygen) plus iPhone data. Request read scopes per category with granular consent; use observer queries + background delivery so new samples sync without opening the app. Optionally write NutriSync's predicted period/phase back to Apple Health.
Android: Health Connect (Google Fit is deprecating) — equivalent read permissions and background sync.
Auto-map: energy proxy ← HRV + sleep; MovementLog activities ← workouts; Phase Confidence ← skin/wrist temperature trend.

A2. Dedicated wearables (Y1–Y3, per deck)

Oura and Garmin via their partner/health APIs (OAuth2); Fitbit/Whoop optional.
Cloud-to-cloud pull on a schedule + webhook where offered; store only derived metrics, not raw firehose.

A3. Sport / activity apps

Strava (OAuth2 + webhook) and native workouts → auto-populate the MovementLog checklist (intensity tags already defined in movement_activity). User confirms/edits.

A4. CGM (Series A / Y3)

Dexcom and Abbott Libre APIs — glucose curve as an advanced biomarker layer.

A5. Connector UX & technical requirements (all new screens, none built yet)

"Connections / Integrations" settings screen (not in Figma): list of providers, connect/ disconnect, last-sync time, per-metric toggles, connection health/errors.
Optional onboarding step: "Connect a wearable" (skippable) after Consent.
Permission priming screens before the OS health prompt (raise grant rates).
Secure token storage (Keychain / Keystore), token refresh, revoke on disconnect.
Background sync scheduling; offline queue; de-dup and conflict rules (manual log vs device).
Attribution/trust rule: device data augments but never silently overrides a user's manual log — show source badges.

B. Data rights & account lifecycle (GDPR, health = special-category data)

The Dev Spec names these in §13.5. Two are already built (export, in-app delete of the user's data); the rest still need full flows, backend, and legal handling. All are MVP / launch-blocking for an EU health app.

B1. Export / "Download my data" — BUILT (in-app JSON export)

Settings → Data Privacy ships a working in-app JSON export of the user's data (profile, cycles, all four daily logs, CAS history, preferences) on both mobile and web.
To extend: add CSV alongside JSON, cover any connector-derived data once connectors exist, and move large exports to an async job → secure, expiring download link delivered in-app + by email.
Covers GDPR right to access and data portability.

B2. Delete data / Delete account — PARTIAL (in-app delete built; auth-record erasure pending)

The in-app delete account flow ships today and erases the user's Supabase rows (all RLS-scoped to their auth.uid()).
What's still needed: wiping the underlying Supabase Auth record itself requires a service-role Edge Function. The service_role key must never ship client-side (it bypasses RLS), so a server-side function is the correct — and pending — mechanism to complete a true hard delete.
To harden: explicit type-to-confirm, a short grace/undo window, and cascade to revoke all third-party grants (HealthKit authorization, Strava/Oura/Garmin tokens) once connectors exist, plus purge of exports/backups per retention policy.
Apple App Store requires in-app account deletion — the in-app delete already satisfies the submission gate; the service-role function closes the compliance loop.

B3. Close / deactivate account (soft) — not built

Offer deactivate (reversible, pauses processing) as a lighter step distinct from delete — reduces accidental hard-deletes and churn-by-mistake.

B4. Consent & processing controls (Dev Spec §13.5, §3.8) — partial

Granular, withdrawable toggles: Analytics & crash reports / Personalised insights / Research participation. Withdrawal takes effect immediately and propagates to processors.
Activity log ("Manage activity log"), cookie/tracking preferences, view Privacy Policy & Terms.
iOS App Tracking Transparency prompt; keep HealthKit data out of any ads/analytics per Apple's HealthKit policy (no selling/advertising use of health data).

B5. Rectification & transparency — built (edit) / partial (disclosure)

Edit personal info (Dev Spec §13.2) satisfies right to rectification — the Personal Information screen ships today.
Clear, per-connector disclosure of what's collected and why (layered privacy notice) is pending the connectors.

C. Cross-cutting mobile capabilities implied (also absent from Figma)

Auth hardening (Dev Spec §13.4): TOTP 2FA, passkeys / biometric unlock (Face ID / Touch ID), active-sessions list with remote log-out per device. Intentionally deferred for now (password auth ships today).
Push notifications & reminders (Dev Spec §13.1): an in-app Notification Center already ships (a live feed from real cycle/phase/logging state), plus a Notifications & Reminders settings screen. True OS push delivery and quiet-hours scheduling are the remaining pieces.
Permissions matrix: Health, Notifications, Location (city), Motion, ATT — each with a rationale screen and graceful denial handling. (Health/Motion arrive with the native build.)
Offline-first sync: local cache + write queue so the real-time CAS keeps working without signal; reconcile on reconnect.
Health-data compliance & security: EU data residency (Phase 1 region is EU), encryption in transit + at rest, HealthKit/Health Connect entitlements, GDPR special-category safeguards, DPA with processors.
Localisation: EN + ES at minimum (testers in Madrid), metric/imperial units. An App Preferences screen (units / week-start / haptics / appearance) already ships on-device.
Accessibility: dynamic type, VoiceOver/TalkBack labels, contrast (see accessibility review).

Suggested priority for the build

Already shipped: in-app JSON export (B1), in-app account delete (B2, user data), Notification Center + reminders UI (C), App Preferences & Nutritional Preferences (C), Personal Information / rectification (B5).

MVP / launch-blocking (next): service-role Edge Function for full auth-record deletion (B2), consent controls + record layer (B4/WF-1), then the native dev build to unlock HealthKit + Health Connect (A1).

Fast-follow (Y1): Strava + Garmin (A3/A2), Connections screen (A5), deactivate (B3), 2FA + biometric unlock (C), offline sync hardening.

Later (Y2–Y3, per deck): Oura (A2), CGM (A4), write-back to HealthKit, research-data pipeline.

What this adds to the app we're building

Screens/modules still to add to the Expo app (the connector set needs the native build): Connections (integrations list + per-provider detail), permission-priming screens, an onboarding "Connect a wearable" step, and — extending the Data Privacy flow that already ships — consent toggles, activity log, and deactivate, plus Sign-in & Security hardening (2FA, passkeys, sessions). Export and delete are already in place.

References

Wearable market data (used for the top-8 ranking, §A0): - IDC — Worldwide Wearable Devices Market Share (vendor tracker): https://www.idc.com/promo/wearablevendor/ - Statista — Wearables market share by vendor, quarterly 2025: https://www.statista.com/statistics/435944/quarterly-wearables-shipments-worldwide-market-share-by-vendor/ - Statista — Wearables: statistics & facts: https://www.statista.com/topics/1556/wearable-technology/ - Grand View Research — Wearable Technology Market Size, Share Report: https://www.grandviewresearch.com/industry-analysis/wearable-technology-market

Connector / platform developer documentation: - Apple HealthKit: https://developer.apple.com/documentation/healthkit - Android Health Connect: https://developer.android.com/health-and-fitness/guides/health-connect - Samsung Health SDK: https://developer.samsung.com/health - Fitbit Web API: https://dev.fitbit.com/build/reference/web-api/ - Garmin Health API: https://developer.garmin.com/gc-developer-program/health-api/ - Huawei Health Kit: https://developer.huawei.com/consumer/en/hms/huawei-healthkit/ - Oura API v2: https://cloud.ouraring.com/v2/docs - Strava API: https://developers.strava.com/ - Dexcom API: https://developer.dexcom.com/ · Abbott Libre: https://libreview.com/

Internal source documents: - NutriSync Collective — Complete Product & Developer Specification, v1.0 (June 2026): §6 (CAS), §13 (Settings/Privacy). - NutriSync investor deck / business case (June 2026): wearables strategy (HealthKit + Google Fit M4, Oura + CGM Y3).