SwiftUI
iPhone, Apple Watch and Mac interfaces adapted to each screen, accessible components and native navigation.
Built in
Technical overview
Gymios,
Gymios,
under the hood.
A precise look at the architecture, data trade-offs and Apple integrations. Statuses separate what’s built into the code from what still needs validation on real hardware.
Gymios for iPhone and Apple Watch is available on the App Store. The Mac version will come later.
- 01Apple HealthMain source for compatible fields
- 02Verified sourceDevice or confirmed import
- 03Gymios supplementOnly when information is missing
Origin kept · no made-up values
Priority rule
Apple Health is never overwritten.
For the information Apple Health exposes, Gymios treats that source as the reference. Gymios data can fill in a missing field, but it never silently replaces an existing value in Health.
-
01
Read Apple Health first
Weight, height, sleep, heart rate, state of mind or workouts are only used after permission, with their date and source.
-
02
Check other sources
Bluetooth data, a recognized document or an imported entry keeps its origin. Unverified sensitive values remain to be confirmed.
-
03
Fill in what’s missing
The Gymios profile and questionnaires only ask for missing information. Declining or skipping a data point doesn’t block the analysis of everything else.
-
04
Write only with consent
An outdoor activity, a compatible reading or a check-in is only added to Apple Health after the matching permission. Importing a Gymios backup neither changes nor deletes Health data.
| Source | Role | Control | Overwrites Apple Health? |
|---|---|---|---|
| Apple Health | Reference for compatible fields | Apple permissions by category | Not applicable |
| Device or import | Traceable additional reading | Technical and human validation | No |
| Gymios entry | Fills in missing information | Explicit user action | No |
| Gymios analysis | Derived, explainable observation | Time period, sources and coverage visible | No |
Native Apple architecture
Each framework has a clear scope.
Gymios is built as a native SwiftUI app. System integrations are isolated so that a declined permission doesn’t disable modules that don’t depend on it.
SwiftData
Workouts, nutrition, confirmed readings, goals and preferences stay available locally.
Built inHealthKit
Reading and writing by category, centralized permissions, origin tracking and no general backup to CloudKit.
Device validationWatchConnectivity
Workout continuity, planned routes and transfer queues that can wait for the connection to return.
Validation on a real pairMapKit + Core Location
GPS track, pace, splits, routes that follow roads, GPX import/export and outdoor activity library.
Long-duration validationPrivate CloudKit
Optional sync of explicitly allowed categories in the private database of the Apple Account.
Off by defaultCore Bluetooth + FTMS
Detection of standardized treadmills, bikes and rowers, without promising compatibility before the model is tested.
Hardware validationVision + OCR
On-device recognition of labels, foods and candidate values, always shown before confirmation.
Built in
Detailed catalog
Advanced features, area by area.
The “built in” status describes the available code. It doesn’t replace device testing, manufacturer agreements or the professional validations indicated.
Training
Built in- Library of ready-made workouts, favorites and custom workouts
- Recommendations based on goal, level, duration, equipment and preferences
- Work/rest timers, workout recovery and Watch transfer
- Instructions, muscle areas and movement demonstrations
- Goals covering strength training and outdoor activities
Outdoor activities and routes
Field validation- Walking, running and cycling with GPS recording started by you
- Distance, time, speed, pace, pauses, elevation gain and splits
- Renamable history, favorites, ratings from 1 to 5 and sorting
- Routed itinerary creation on Mac and transfer to iPhone/Watch
- GPX/TCX imports and exports, off-route alert and protected recovery
Health and check-ins
Real HealthKit required- Single Apple Health permissions center
- Weight, height, sleep, heart, recovery and visible sources
- Optional questionnaire filling in missing information
- Apple Health state of mind takes priority when available
- Adaptive observations without made-up data or diagnosis
Nutrition
Confirmation required- Meal journal, portions, hydration and trends
- Library built from sourced nutrition data
- Open Food Facts barcodes without sending Health data
- Label OCR and on-device photo recognition
- Missing values shown as unavailable, never made up
Connected devices
Model by model- FTMS for compatible treadmills, bikes and rowers
- Scales through Apple Health
- Blood glucose imports bounded, quarantined, then confirmed
- Brand-by-brand pairing help without false promises of support
- Read-only preferred to avoid any unintended command
Community and consent
Foundations built in- Module off by default and revocable at any time
- Optional username, private profile and chosen visibility
- iCloud sync limited to non-medical preferences
- No automatic import of the address book
- Private codes, invitations, blocking and reporting built in; moderation procedure to be validated before opening
Goals and trophies
Sharing by choice- Personal goals, day streaks and visual celebration
- Vertical showcase with three trophies per shelf on iPhone and Mac
- System sharing of a summary chosen by the user
- Optional Game Center, limited to the achievement identifier and progress
- Posting to the circle or community linked to the Gymios HTTPS service, with Sign in with Apple required
Coach role
Setup and testing in progress- Role declared by the person: Gymios doesn’t verify qualifications and asks for no supporting documents
- Designed for a coach you already know, for example at the gym, who invites you with their code
- Sign in with Apple verified on the server; refresh token kept encrypted to revoke the sign-in when the account is deleted
- No data shared without your consent, category by category, with an end date
Local analysis
Lab- Cross-referencing only the categories actually available
- Time period, coverage and origin attached to observations
- Optional Apple Intelligence to reorder findings already calculated
- No direct model access to Apple Health
- No raw medical documents, free-text notes or detailed GPS tracks sent
Apple continuity
Signing to be validated- Widgets, complication, Smart Stack and Live Activity
- App Intents, Siri shortcuts and deep links
- Separate customization of iPhone and Mac spaces
- Watch home with essential shortcuts
- Standard fallback when a new system feature isn’t available
Community and coach circle
Share less,
Share less,
but share it clearly.
The public community and private coach follow-up are two separate spaces. Turning one on never automatically gives access to the other.
The module stays private and off at first. The user then chooses their username, visibility and each connection.
Settings built inTrophies are only posted after permission. Coach profiles only include the checked categories and flag highly sensitive data separately.
Implemented, service to be deployedThe coach role is a simple declaration. Gymios doesn’t verify qualifications: you only share with someone you know.
ImplementedRecipient, purpose, categories, period and expiration are set before access. Server-side revocation is immediate and cuts off the shared profile.
Policy and service built in
Always excluded from coach sharing
Blood glucoseReproductive healthMedical documentsApple Health in iCloud
The coach never views Apple Health directly. Profiles are prepared on device from a closed list of allowed categories, then encrypted on a service separate from iCloud.
Data boundaries
What leaves the app — and what doesn’t.
Each channel has its own allowlist. Turning on a sync doesn’t automatically give access to other categories.
Workouts, nutrition, confirmed readings, goals and working data stay on the device.
By defaultReading or writing only for the categories chosen in Apple’s secure interface.
By categoryRoutines and scheduling; planned routes and GPS history recorded by Gymios only with two separate consents. Outdoor activities imported from Health, heart readings and zones, blood glucose and nutrition are excluded.
OptionalAchievement identifier and completion percentage, with no Health readings or detailed route.
OptionalOnly the barcode is sent over HTTPS to look up the product details.
Third-party serviceNon-medical preferences in iCloud; identity, connections, trophies and coach profiles on a separate service, with sensitive content encrypted at rest. The HTTPS API is deployed; opening awaits Apple’s production setup and moderation validation.
API deployed
Level of evidence
Compiling isn’t validating.
The technical documentation separates four levels of evidence. The steps below describe the expected checks; validation on hardware and in distribution is still in progress.
1Code built in
Compile the feature and test its automatable rules.
2Simulator
Check the interface and scenarios locally without sensors.
3Real hardware
Test GPS, Watch, HealthKit, Bluetooth, battery life and interruptions on devices.
4Distribution
Check signing, privacy, accessibility and Apple requirements for the distributed version.
Health scope
Gymios presents personal logs, trends and observations. The app is not a medical device, a diagnosis or a treatment, and doesn’t replace any health, sports or nutrition professional.
Follow the real status of features
The roadmap separates what’s built in, what’s being validated and future ideas.