Note: on devices WITH A GYROMETER the newest iOS Update filters the raw data along with gyro data. Here you CAN NOT use the magnetometer as shown in video any more! As soon we can work around this, we will update the software (but can not promise this will be possible!)

The first and only Vector Magnetometer on the iPhone 3GS! - Visualize the hidden world of magnetism around you in 3 dimensions (3GS or later!)! It can be perfectly used to explore and measure the direction and strength of the magnetic field of random objects around you (which can be quite fascinating!). With limitations (see docs) it can be used as a metal detector to find electric lines or pipes in walls (always good to check a wall before drilling in, at least better with this than not to check at all). Another application is to use this tool as a rough estimate of your north-south position on earth without using the GPS(!) - just by measuring the local earth magnetic declination (it works fine even while flying in a plane to check how the declination changes). Or simply explore your next Christmas present before opening it! Send us your results!


The application has four different displays modes to visualize the magnetic field:

✔ Absolute Mode: Displays the absolute magnetic field in microtesla (μT) measured by the magnetometer.

✔ North Mode: A compass head-up displays the geographic north along with the pointer that directs to the magnetic north (thus display difference magnetic to geographic north).

✔ Declination Mode: Two arrows will be displayed to indicate the declination of the earth magnetic field (0° just on equator, increasing to north with blue pointer direction up or south with blue pointer direction down).

✔ Relative Mode: This mode shows the relative strength (absolute minus compensation vector) of the magnetic field in μT.


… and five different display modes for acceleration visualization:

✔ Absolute Mode: Displays the reverse acceleration of the iPhone (1g up when hold steady).

✔ X-Rotation ✔ Y-Rotation ✔ Z-Rotation: The arrow will display the rotation around the X-, Y- and Z-Axis of the iPhone. The digital indicator shows the angle numerically (-180° - +180°). A way to calibrate will be added with one of the next updates, so you could use this as a level.

✔ Relative Mode: This mode shows the relative strength (absolute minus compensation vector) of the acceleration.


For a detailed documentation, please visit our product homepage.


For recreational use only. However it CAN (!) be very accurate. The measurement is performed as good as possible (we try our best) by using the inbuilt accelerometer and magnetometer to their limits. The range of the accelerometer typically has a max of ±3g (~4.2g displayed here if combined) and each magnetometer usually recalibrates internally when over ±120μT in one axis. However, tell us your experience!

On a Non-3GS device the MagnetMeter functionality is limited to acceleration only. This is intentional on a NON-3GS device, as it does not have a magnetic sensor. Please don't give us bad ratings for that: You can grab the AccelMeter for free and keep this app for the future!