Rocklogger is a rock logging app for geologists with an Android phone. It uses the phone’s orientation, compass and GPS sensors to measure either dip & strike, or dip & dip direction of rock outcrops. It can also save the ambient magnetic field.
Data is saved in CSV format, which can be transferred by email or usb to computer, for use in geology/mapping applications (eg Mapinfo).
Taking the dip and strike of outcrops with a compass/declinometer usually takes a few minutes per rock. With Rocklogger, many measurements of an outcrop can be taken in seconds.