MagSense - An Earth magnetic field and GPS location monitoring tool for earthquake research

Some earthquake experts found that before a big earthquake comes, there might be a magnetic field disturbance. This app is able to keep monitoring the magnetic field variation and its location and give alarm if the magnetic field variation exceeds a threshold value. The raw data of time, magnetic field, and location record can be downloaded to computer through iTunes for further analysis. (Continued use of GPS running in the background can dramatically decrease battery life.)