*** This App only works with an Oximeter device. *** This is a personal health management service for measuring oxygen saturation (SpO2). It would help if you used it with a Bluetooth pulse oximeter. The app allows you to measure blood oxygen saturation (SpO2), pulse rate (PR), and perfusion index (PI) noninvasively; it is free, and you can use the app to display, record, and view your measured data. You can also click any point in the historical trend to learn more about your measurement data and manage your health status. Features: （1） One step connection to Bluetooth pulse oximeter （2） Fast measurement and real-time display （3） Track and trend your measurement history SpO2%--Percentage of functional arterial oxygen saturation Pulse Rate-- Beats per minute (BPM) Perfusion Index--Pulsating blood flow(PI%)