This app claims to let users monitor SpO2 levels and pulse rate with your smartphone: Here's how it works | Tech News
Bluetooth Pulse Oximeter Finger Monitor by Wellue,Fingertip Blood Oxygen Saturation Monitor for Sports Home Wellness,Free App for iOS and Android,FS20F Black - Walmart.com
Finger Pulse Oximeter Pulse Rate Blood Oxygen Saturation Monitor w Bluetooth App | eBay
Amazon.com: LOOKEE Ring Continuous Pulse Oximeter | Bluetooth & Wearable Oxygen Monitor with Vibration Reminder for Low O2 | Rechargeable Blood Oxygen Saturation Tracker for SpO2 & PR - Free APP with
Wellue O2Ring Oxygen Monitor with Vibration Reminder (Adults) - Blueto