This is an App that use Apple Watch as magnetic detector.

Swiping left on the screen displaying the analog clock opens the settings screen. In the settings screen, there are two buttons in the first row; the left button is for turning the sensor on and off, and the right button is for turning notifications on and off.
Turning on the sensor will display buttons to open other items' settings screens, such as threshold, attitude, notification interval, and a screen showing the magnetic field currently being detected by the sensor.

Setting the threshold will trigger notifications when a magnetic field stronger than the set threshold is detected.

The angle allows you to specify the range of pitch and roll angles, so that notifications only occur when the arm is within a certain range of angles (actually determined by the tilt of the device, so it does not accurately reflect the arm's angle).

The notification interval allows you to set the time until the next notification.

Occasionally, the sensor may not start, or it may stop due to processing delays. Opening the magnetic field display screen will show the current magnetic field, and if all values are "0.00", it can be determined that the sensor has stopped. In this case, toggling the sensor on and off will restart the sensor later.

On the analog clock screen, when the sensor is activated, the second hand is displayed, and when notifications are on, a rectangle (with serrated edges just inside the circumference) is displayed.

Points to Note:
- This app offers detailed settings, but as a result, its operation is more complex compared to SMD.
- Increased accuracy makes it more sensitive to the orientation of objects.
- Due to changes in detection principles, it is more affected by case and band materials compared to SMD.
- More sensor data and processing steps mean higher battery consumption at startup.
- It works with Apple Watch series7 and later, but series8 and later are recommended.

"Supports Japanese, English, and Chinese."