Bad UX
Some instructions would help!!! Can't figure out how it works....

Transform an old iPhone into a baby monitor that alerts you via phone call or email when your baby moves or cries. It uses the accelerometer to detect positional changes and allows you to speak to your baby through the device.
1.3.0
April 13, 2020
iOS 13.3 Support
BabyGuard uses the iPhone's accelerometer to detect any significant tilt or positional change, indicating your baby has woken up or moved.
BabyGuard is designed to run on iPhones and iPods, making it ideal for repurposing older Apple devices.
BabyGuard is a paid application, available for a one-time purchase price of $4.99.
Yes, BabyGuard allows you to hear if your baby is crying and respond with a parent's soothing voice through the old iPhone.
No, BabyGuard is ad-free, providing an uninterrupted monitoring experience for parents.
The latest version of BabyGuard, 1.3.0, was last updated on April 13, 2020.
BabyGuard has an age rating of 4+, making it suitable for use by parents of young children.
BabyGuard disregards the first 20 accelerometer readings and then generates an average from the next 20 to establish a base location for monitoring.