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Heart Monitor: Wearables Integration That Gives 90,000 Active Users a Complete Picture of Their Health
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Integration
Full coverage
Experience
Instant connect
Ownership
Data control
Delivery
One Week
Scale
90,000+ active users
Most health apps track what you do inside them. Heart Monitor wanted to track what your body actually does.
With 90,000+ active users across Google Play and the App Store, Heart Monitor had already built something people wanted: a clear, intuitive way to understand and improve personal health. But a growing share of their users wore Garmin watches or synced with Apple Health, Samsung Health, and Google Health Connect. That data lived in separate apps, in separate ecosystems, and Heart Monitor couldn't use any of it.
The opportunity was obvious. The execution was not.
Building wearable integrations from scratch means dealing with multiple OAuth flows, different data models, different rate limit policies, and months of engineering work before you ship a single feature. For a team focused on product, that's the wrong problem to spend time on.
That's where Open Wearables came in. Momentum provided the open-source platform, deployment infrastructure, and implementation consulting. The Heart Monitor team integrated it into their existing stack and went from decision to production in weeks, not months.
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What we were up against
Heart Monitor faced a challenge that many consumer health apps hit as they scale: the product works, the users are engaged, but the data that would make the experience genuinely complete is locked in third-party ecosystems.
Fragmented user data across providers
Users don't wear one device or use one platform. A typical Heart Monitor user might track workouts on Garmin, runs on Strava, and steps via Apple Health or Google Health Connect. Each provider has its own API, authentication system, and data format. Building and maintaining native integrations for all of them would have required a dedicated team and months of work before any user value was delivered.
Per-user pricing doesn't work at scale
Every commercial wearable API on the market charges per connected user. For an app with a large free-tier user base at scale, that model makes the feature economically unviable before it ships. And there was no self-hosted, open-source alternative that matched the provider coverage Heart Monitor needed. Until Open Wearables.
Keeping health data in the right hands
Health data is sensitive. Routing user biometrics through a third-party cloud creates compliance surface area and erodes user trust. The team needed a solution that kept data on their own infrastructure, under their control.
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Four things that had to work perfectly
Connect users to their devices without friction
Build a seamless in-app OAuth flow for every supported provider, so users could connect their wearables in seconds without leaving Heart Monitor.
Normalize data into a single, usable schema
Eliminate the inconsistency between providers so the Heart Monitor health intelligence layer could consume wearable data without custom handling for each device type.
Keep infrastructure costs predictable
Avoid per-user pricing entirely. The cost of the wearable data layer should scale with infrastructure, not with user count.
Self-host by default
Keep all user health data within the client's own infrastructure. No third-party cloud. No data routing through external services.
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What Momentum delivered
Momentum's role was threefold: open-source platform, infrastructure, and implementation consulting. The Heart Monitor team drove the integration on their end. Momentum made sure they had everything they needed to do it confidently and quickly.
Open Wearables platform
Momentum built and maintains Open Wearables: a fully open-source wearable data platform covering all major providers. It includes a REST API, native mobile SDK for iOS and Android, provider OAuth handling, data normalization layer, and Docker-based deployment. Heart Monitor got access to the full codebase from day one.
Deployment infrastructure
Momentum provided the infrastructure layer: Docker Compose setup, environment configuration, and a deployment model designed to run entirely within the client's own servers. No external dependencies, no data leaving the client's infrastructure.
Implementation consulting
Momentum worked with the Heart Monitor team to map their existing Hasura/GraphQL data model to the Open Wearables schema, select the right API endpoints, validate provider configurations, and unblock technical questions during the integration process.
Ongoing technical support
After launch, Momentum remained available for technical support: provider API changes, sync edge cases, and platform updates as Open Wearables continues to evolve.
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How it came together
Platform and documentation handoff
The Heart Monitor team started from the Open Wearables open-source repository. Momentum's documentation covered SDK setup, provider configuration, and deployment, reducing ramp-up time significantly.
Data model alignment
The Heart Monitor team mapped their existing backend to the Open Wearables normalized schema, with Momentum providing consulting support to validate the approach and advise on endpoint selection.
Provider integration and testing
The Heart Monitor engineering team configured OAuth flows, token refresh logic, and sync schedules for all supported providers, tested against real device data before going to production.
Production deployment
Heart Monitor deployed Open Wearables entirely on their own infrastructure. Momentum provided technical support throughout and remained on hand after launch.
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The tech behind the integration
The integration was designed to be additive: it extended Heart Monitor's capabilities without introducing new architectural constraints or external dependencies.
Open Wearables
Open-source wearable data platform built by Momentum. Handles provider authentication, data normalization, and sync. Self-hosted on the client's own infrastructure.
Flutter
Heart Monitor is a cross-platform mobile app built in Flutter. The Open Wearables native SDK integrates directly into the Flutter codebase for Apple Health (iOS) and Health Connect / Samsung Health (Android).
Hasura + GraphQL
Normalized wearable data is upserted into the Heart Monitor backend via Hasura's GraphQL API, fitting naturally into the existing data layer without architectural changes.
Docker Compose
Deployment via Docker Compose ensures the integration runs in a controlled, reproducible environment without requiring changes to the existing production stack.
Provider integrations at launch
Apple Health, Google Health Connect, Samsung Health (native SDK) + Garmin, Polar, Strava, and other cloud OAuth providers.
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What we achieved together
Heart Monitor's 90,000+ active users now have access to a complete health picture inside a single app. The product is more valuable, the data is richer, and Heart Monitor owns all of it.
Full provider coverage, live in production
All major wearable providers integrated and running reliably. OAuth flows, token refresh, and data sync working across all supported devices.
User experience that works
Users connect their devices in seconds from inside the app. Wearable data appears alongside existing Heart Monitor health data. No switching apps, no manual logging.
Single engineer, approximately one week
The full integration (SDK setup, OAuth flows for all providers, data normalization pipeline, production deployment) was completed by a single Heart Monitor engineer in approximately one week.
Complete data ownership
All user health data stays in Heart Monitor's own infrastructure. No third-party cloud routing. Full control over data access, retention, and compliance posture.
Foundation for future health intelligence
With a normalized wearable data layer in place, the Heart Monitor team can now build richer health scoring, trend detection, and personalized insights on top of real biometric data from all connected devices.
Heart Monitor came to us with a clear problem: 90,000+ active users whose health data was scattered across devices and apps, and a product that couldn't use any of it. Momentum delivered Open Wearables (the open-source platform, deployment infrastructure, and implementation consulting) and Heart Monitor's team took it to production in a matter of weeks.
The result: full provider coverage, complete data ownership, and a wearable data layer that scales with their infrastructure rather than their user count.
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