This article discusses issues related to the alarm functionality in Pillow. If the alarm did not go off please check the following:
Use Pillow with your iPhone
Due to technical limitations imposed by watchOS alarms are not possible using the Apple Watch only. If you want an alarm or audio recordings you must also use the iPhone as follows: Open Pillow on your iPhone › Set your desired alarm time › Keep Pillow on the iPhone running (do not press the home or side buttons) › Open Pillow on the Apple Watch and tap 'Start' › › Make sure ‘Alarm’ is checked › Press 'Next' to start your session.
Select a mode that supports alarms
Pillow comes with a variety of sleep modes that help you track your sleep but not all of them use an alarm. To ensure you are recording Pillow with a mode that supports alarms: Open Pillow on the iPhone › Swipe upwards right above the “Start” button › Make sure you have selected either: “Full mode” or “Sleep Cycles + Alarm” or “Alarm Only”
Important: Pillow does not support alarm presets, so you have to start a recording session manually before going to sleep.
Make sure your iPhone or iPad is on the charger
Pillow performs processor-intensive tasks that can consume battery, that is why we recommend that you keep your device on the charger during the night. If you don’t iOS might disable apps that run in the background, like Pillow to preserve battery.
Make sure Pillow is not in the background
While Pillow can run in the background we strongly recommend that you keep it open during the night.
Alarm from iTunes
Alarm sounds selected by your iTunes library will not play unless Pillow is running in the foreground at the time of the alarm. You can switch between apps after starting a sleep session but remember to return to Pillow and keep it running in the foreground (do not press the home button or lock your device).