NoctO₂ turns your Bluetooth sleep oximeter into an overnight monitor on your iPhone, with live SpO₂ and pulse, alarms you control and, if you want, a heads-up to your family.
Free on iPhone. No account to create, nothing to sign in to.
Put your ring or wrist oximeter on and tap “Add a device”. It’s found over Bluetooth in seconds. Which devices?
Pick your limits in the Alerts tab, put the iPhone on its charger, and go to sleep. Add your family if you like.
Wear your ring, put your iPhone on the charger, and go to sleep. NoctO₂ keeps an eye on things.
Big, clear readings from your oximeter, with a running chart, your lowest value and time below your limit.
Low oxygen, high or low pulse, ring off finger, low batteries. You set the limits, how long to wait and how often to remind.
If an alarm isn’t answered with “I’m OK”, the people you choose get a notification on their iPhones.
Download the recordings stored on your ring and look back at each night’s average, lows and pulse.
Your readings stay on your phone. No account, no ads, no tracking.
Works with the screen locked, keeps going on the charger, and has a backup alert if the readings ever stop.
Short dips happen. Choose how low, and for how long, before NoctO₂ sounds an alarm. Then tap “I’m OK” to stop the reminders.
For a parent living alone, a partner who travels, or anyone who sleeps through their own alarms. If an alarm isn’t answered in time, the family is told.
See how the night went at a glance: average and lowest SpO₂, time below your limit and pulse. The full chart is one tap away.
Bring the ring or wrist oximeter you already have. More devices are added over time.
Live readings only. The SP-20 doesn’t share stored recordings over Bluetooth.
Live readings. Not yet tested on a real device.
See every device in detail, with links to the makers →
No oximeter yet? Try Demo Mode in the app’s Settings to see a simulated night, alarms included.
NoctO₂ keeps your readings on your iPhone. Nothing is sent anywhere unless you set up family alerts, and then only what your family needs to see.
Yes. No subscription, no in-app purchases and no ads.
Yes. Keep your iPhone on the charger near your oximeter. Monitoring continues with the screen off, and a backup alert warns you if the readings stop.
An oximeter connects to one app at a time, so close the other app while NoctO₂ is monitoring. Your oximeter keeps its own recordings either way.
No. They just install NoctO₂, open the Family tab, choose “I’m a family member” and enter the code you give them.
Add NoctO₂ to the allowed apps of your Sleep Focus or Do Not Disturb, and keep Time Sensitive notifications on. The support page walks you through it.
Not yet. NoctO₂ is iPhone only for now.