Sleep Cycle has two motion detection modes, microphone or accelerometer.
You can change modes under:
Profile > More > Motion detection
Microphone for iOS
The built-in microphone is used to analyse your movements as you sleep. Keep the app running in the foreground with the device unlocked. It’s important that you place your phone correctly. Note that iPhone 8 and X can be placed facing up.
It’s important that you place your phone correctly:
Accelerometer
The accelerometer is used to analyse your movements as you sleep. Keep the app running in the foreground with the device unlocked. It’s important that you place your phone correctly:
Depending on your type of bed and mattress you might find certain placements work better. Please do not place your phone underneath a pillow or thick mattress as it can become warm when charging.
If you feel uncomfortable having your phone close to your head, you may set it to Flight Mode. Keep the app running in the foreground with the device unlocked. As a bonus this also ensures that no one can bother you while you sleep.
