React Native Expert Needed for Google Fit & Health Connect Integration (iOS/Android)

We are looking for an experienced React Native developer with proven expertise in integrating:

* Google Fit
* Android Health Connect
* Apple HealthKit (preferred)
* Fitness/health data synchronization APIs

for both Android and iOS applications.

## Project Overview

We are developing a health and fitness related mobile application that requires capturing user health/activity data, such as:

* Steps
* Distance
* Heart Rate (HR)
* Calories
* Activity/Workout data
* Other supported health metrics

The app will securely collect this data and publish/sync it to our backend API/cloud platform.

## Critical Requirement – Data Accuracy & Reliability

This project is NOT just about reading data from Google Fit or Health Connect.

Data accuracy, consistency, and completeness are extremely important.

The selected freelancer must have experience handling:

* Accurate health data synchronization
* No skipped or missing records
* Proper historical data fetching
* Reliable background sync behavior
* Duplicate handling and data consistency
* Correct timestamp and timezone handling
* Stable syncing across app restarts/device states
* Efficient batching/uploading to APIs/cloud

We are specifically looking for someone who understands real-world challenges with fitness/health data integrations and can deliver production-quality reliability.

## Important Requirements

Only apply if you have REAL production experience working with:

* Google Fit APIs
* Android Health Connect
* Apple HealthKit
* React Native mobile apps

You MUST provide:

1. Links to published apps you have worked on
2. Description of your role in those projects
3. Specific health/fitness data integrations you implemented
4. Screenshots/videos/demo if available
5. Technologies/libraries used

Applications without relevant portfolio examples will not be considered.

## Scope of Initial Work

Selected candidate will receive detailed project requirements and will first be expected to deliver a working prototype/demo application for:

* Android
* iOS

The prototype should demonstrate:

* User permissions flow
* Reading health/activity data
* Reliable sync to API/cloud endpoint
* Accurate and complete historical data retrieval
* Stable background/foreground sync handling
* No missing/skipped health records

## Preferred Skills

* React Native
* Google Fit API
* Android Health Connect
* Apple HealthKit
* REST APIs
* Firebase/AWS experience is a plus

## Deliverables

* Working prototype app (Android & iOS)
* Source code
* Documentation/setup instructions
* Clean and scalable implementation
* Reliable and accurate data sync implementation

## To Apply, Please Answer:

1. Which apps have you built that use Google Fit / Health Connect / HealthKit?
2. What data types did you integrate?
3. How did you handle accurate syncing and prevent missing data?
4. Have you implemented background sync?
5. Can you deliver both Android and iOS prototypes?

We are looking for someone who can start immediately and has hands-on experience solving real-world health data integration and synchronization challenges.