HealthKit

Apple Health Kit intends to be a personal and central data collection point for medical and fitness purposes. On one hand it allows users to monitor and review their health indicator from single application, and on other hand allows third-party electronic accessories and wearable technology to push data to phone.  In short, HealthKit was introduced in iOS8 as a single place where apps can store, share, and read health-related data. Many developers have already started taking advantage of health-kit on iOS and we strongly believe that Health Kit will become standard for monitoring personal health.

Guidelines for using Health Kit SDK’s into native iPhone applications

1. The HealthKit framework is available since iOS 8. Note that it’s only available on iPhone, not iPad.
2. You must explicitly request access to read and/or save to HealthKit for each data type you need to access. The user has the option to allow access for some types of features and deny it for others depending on his choice. Data type includes blood pressure, Body Fat percentage, Weight etc
3. You won’t be able to read from HealthKit when your app is in the background. Automatic saving to HealthKit, however still works even when the phone is locked.
4. You must explain in your App Store description and in your app how your app will use the data obtained from HealthKit. Failing to do so might result in rejection of your app.
5. There is a new section in the App Store review guidelines that covers HealthKit. You should definitely read through it before you decide whether to add support for HealthKit or not.
6. Once your app integrates with HealthKit, you must provide a privacy policy for it. Apple even recommends some documents that specify what Health-related privacy policies should look like. It’s important that the privacy policy tells the user how your app treats their data.
7. You cannot use data from the HealthKit store to serve ads

Privacy Policy: The HealthKit data is only kept locally on the user’s device. For security, the HealthKit store is encrypted when the device is not unlocked. The HealthKit store can only be accessed by an authorized app. You cannot access HealthKit from extensions (like the Today view) or from a WatchKit app.

Apple Developers Forum

HealthKit Framework

Data Sources for Health Kit: There are two types of data sources for HealthKit store Apps and Devices. Apps can read and write data by asking permissions explicitly for each metric or quantity whereas M7 motion coprocessor and Bluetooth LE Devices can directly input data to system and all other devices can use third party apps to read and write data to HealthKit store

What you can read and write

1. You can read all Characteristics like Date of Birth, Blood Pressure & Gender and Samples like Sleep Analysis, Temperature, Weight & Workouts etc. from HealthKit store.
2. You can write only Samples like Sleep Analysis, Temperature, Weight & Workouts etc to HealthKit store from your apps.

Apps using HealthKit

1. Human – an all-day activity tracker
2. Fjuul – Healthy Activity Coach
3. Argus – Calorie Counter & Activity Tracker for Heart Healthy Living

Note: you can use “Google Fit” Google Fit in Android to achieve same functionality.