SMD - Simple Magnetic Detector

SMD is a watchOS app that uses the Apple Watch magnetic sensors to detect nearby magnetic field changes and provide haptic feedback alerts.

The app supports two operating modes: Manual Mode and Motion Mode.
In Manual Mode, detection can be started and stopped with a tap.
In Motion Mode, raising the wrist starts baseline acquisition, and briefly holding still moves the app into a ready state.
In both modes, detection and alerts become active only after baseline acquisition is complete.

Sensitivity can be adjusted from the Settings screen using the Digital Crown.
The app also supports live X / Y / Z magnetic field display, automatic polarity detection, and mode switching from the Settings screen.

Version 4.0.x uses a single-trigger system to reduce excessive repeated alerts.
Detection normally triggers once per activation, and another trigger requires the magnetic field to fall back below the release threshold.

Key Features
- Magnetic field change detection using Apple Watch sensors
- Haptic feedback alerts
- Manual and Motion modes
- Digital Crown sensitivity adjustment
- Live X / Y / Z magnetic field values
- Automatic polarity detection
- Stable single-trigger alert behavior

SMD is a watchOS app that uses the Apple Watch magnetic sensors to detect nearby magnetic field changes and provide haptic feedback alerts.

The app supports two operating modes: Manual Mode and Motion Mode.

In Manual Mode, detection can be started and stopped with a tap.

In Motion Mode, raising the wrist starts baseline acquisition, and briefly holding still moves the app into a ready state.

In both modes, detection and alerts become active only after baseline acquisition is complete.

Sensitivity can be adjusted from the Settings screen using the Digital Crown.

The app also supports live X / Y / Z magnetic field display, automatic polarity detection, and mode switching from the Settings screen.

Version 4.0.x uses a single-trigger system to reduce excessive repeated alerts.

Detection normally triggers once per activation, and another trigger requires the magnetic field to fall back below the release threshold.

Key Features:
- Magnetic field change detection using Apple Watch sensors
- Haptic feedback alerts
- Manual and Motion modes
- Digital Crown sensitivity adjustment
- Live X / Y / Z magnetic field values
- Automatic polarity detection
- Stable single-trigger alert behavior

Important Notes:
- Magnetic watch bands may cause interference
- Strong magnets may temporarily affect sensor readings
- Apple Watch Series 8 or later is recommended