blood oxygen levels fluctuate, a big variation is a sign of concern, often helpful in screening covid-19 patients. Low oxygen levels could be a symptom of other health issues, too.Unlike standalone oximeters that are clipped on the finger, devices such as Fitbit Versa are worn all the time, and can continuously track SpO2, along with heart rate and other indicators.After the covid-19 outbreak, many users like Koul are turning to smartwatches and fitness bands that can track SpO2 and body temperature.