User Guide

Somno supports automatic sleep tracking using your Apple Watch, including naps as short as 15 minutes.
To enable this feature, please ensure the following:

• Version 2.2.1 or later

• Install and open the Somno Watch App
  Make sure the app is successfully launched on your Apple Watch and initial data sync is completed

• Grant required permissions
  Authorize access to Apple Health, Motion & Fitness, and Notifications on your iPhone

• Enable Background App Refresh
  Ensure that background app refresh is enabled for Somno Watch

Once all the above conditions are met, your Apple Watch will automatically detect and record your sleep when you fall asleep wearing it — no manual action needed.

Can't Detect Naps

Somno determines whether you’ve fallen asleep by analyzing multiple indicators, including heart rate, body movements, and active energy.

The following situations may cause naps to go undetected:

• Missing heart rate data
  Turning off wrist detection, enabling Low Power Mode, wearing the watch too loosely, or sensor issues may result in missing heart rate data. You can check your heart rate in Health > Heart Rate > Show All Data to ensure it’s recorded properly.

• Sleep duration under 15 minutes
  If frequent movement is detected, Somno may determine that you weren’t continuously asleep, and the nap will not be recognized.

• No significant heart rate drop during sleep
  If your heart rate doesn’t drop noticeably, Somno may conclude that you weren’t truly asleep, and the session will be excluded.

No Nap Report Received

The following situations may prevent the nap report from being sent:

• App is running in the foreground
  If sleep is detected while the Watch App is open, no report will be pushed

• Background App Refresh is turned off
  Please ensure that background refresh is enabled for Somno Watch in your Watch settings

• System restrictions on background activity
  These conditions may cause background detection to fail:

  1. Your iPhone is in Low Power Mode or Battery Saver Mode
  2. Your Apple Watch is locked after being taken off

Sleep Data Sync is Slow

Somno relies on the Background App Refresh feature to detect and analyze your sleep in the background.
To conserve power, the detection frequency is intentionally low and is managed by iOS. The system uses your behavior and time patterns to determine which apps can run in the background.

Sometimes, if the system hasn’t yet “learned” your usage pattern with Somno, background execution may be unstable, affecting detection speed.

Recommended tip:
Open Somno at a regular time (e.g., after your nap) for 5–7 consecutive days. This helps iOS learn your habits and prioritize Somno’s background activity during key periods.