Apple’s new HealthKit platform and Health app for iOS 8 acts as a central location for users to store and share health data from third-party apps, but Apple is also supporting some Bluetooth accessories natively in the Health app. That means that some accessory manufacturers will be able to skip the process of developing a companion app for their product and instead allow HealthKit to automatically connect to and control the device itself. 

The accessories that will be built-in and supported natively by HealthKit include heart rate and blood pressure monitors, glucose sensors, and health thermometers. Apple is using official standard specs for Bluetooth LE devices from Bluetooth.org, which is what allows iOS 8 to automatically establish a connection with the devices listed above without the manufacturers worrying about anything on the software side. Not only will HealthKit automatically establish a connection with devices in range, it will also handle gathering data, saving it in the Health app and notifying other apps that might want to access the data via the HealthKit API.

Previously these manufacturers would have to spend time and money developing companion apps for their products that handle the pairing and collection of data. It will also benefit app developers that provide users with the ability to connect to accessories from third-party companies as now they won’t have to write extra code for the pairing and data collection. They’ll just get it from HealthKit instead.

Apple is also allowing and encouraging manufacturers to build other types of accessories that don’t fall under the natively supported devices above, but those will require an iOS app to implement the HealthKit API. Apple is allowing accessories that use the ExternalAccessory framework, CoreBluetooth, USB, or Wi-Fi, but hasn’t discussed any limitations for HealthKit accessories.