Sleep Sound Recorder

Requires an Apple Watch.
When you go to bed, wear your Apple Watch and record sound with this app.
It records one minute of loud sound along with the following data:
- Sleep depth
- Blood oxygen saturation (%)
- Respiration rate (count/min)
- Heart rate (count/min)
The recorded sound can be displayed as a graph.
The app keeps a record of your sleep over the past week so you can see the quality of your sleep.