The SW021 comes with 3 sensors: Accelerometer, Gyroscope, Heart Rate Monitor (HRM). These only cover a few fitness and health areas. These sensors allow you to track the following 6 metrics: Calories, Distance, Heart Rate, Menstrual Cycle, Sleep, Steps.
The Willful SW021 uses the VeryFitPro app,
The SW021 is using a Nordic NRF52840 processor.