Wear OS by Google is an Operating System having in built support for smartwatch sensors and exposes low level hardware via Wear OS SDK. This helps the developers to tap into the rich array of sensors present on the watch and capture data over time to extract meaningful activity information like Average Heartbeat, Calories burnt over a period, Cardiovascular activity performed, Step counter and so on. Developers can build applications to track the human activity and present interactive graphs to maintain and improve the individual health.

Google Fit is an application by Google available on Android and iOS platforms for the purpose of fitness Tracking and analytics. It tracks health of the heart and Activities either by using the sensors present on the wearable or by the companion app present on the paired smartphone.

Fitness Trackers from Fitbit also suggests a custom diet plan based on activity data and calorie expenditure. We can also input data based on our food intake and get information like calorie expenditure per dish/meal. The fitness trackers apply algorithms by using accelerometer and motion sensor data to identify the workout and calories being burnt. These data are usually sent to a companion app on the smartphone or to the cloud so the individual can also view the trend for each data set like heartbeat trend over a week, step count trend for a month, calories burnt throughout the day during different activities like a workout in the gym, walking, running, etc..,