In addition of being an amazing app for research you will also get the chance to look at the magnetic field of the world around you. We are looking at how electronic devices affect their surroundings and doing so by looking at the environmental sensors on the phone (acceleration, gyration, compass, etc) We've done our best to protect everything you share with us and we will show you the results of your contributions. There is a complete information sheet inside if you are curious. Give it a try. It is fun for you and incredibly useful for us.