HEALTH TRACKING DEVICES

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for promoting healthy behavior. The methods, systems, and apparatus include an action of receiving device capability information for multiple devices. The device capability information from each device describes capabilities of the device. Additional actions include receiving an indication of a health goal of a user and receiving health information of the user sensed by a first device of the multiple devices. Further actions include generating a health related instruction for a second device of the multiple devices based on the health information of the user sensed by the first device of the multiple devices, the health goal of the user, and the device capability information of the second device. An additional action includes providing the health related instruction to the second device.