A software application installed on a mobile device moving along a path periodically measures and records a parameter along with the GPS position associated with the measurement. Path data files are recorded on the device's internal memory and may be transferred to and from a repository database to share data between devices. Data may be displayed in the form of a map allowing users to navigate along paths to locations with desired parameter levels. This parameter may be cellular signal strength, allowing users in areas with no usable signal to find a usable signal. If data are preloaded onto a device, signal strength maps can be displayed even when the device has no current data connection. Parameters can be calibrated to compensate for differing sensitivities between device models. Screen dimming and audio cues can reduce battery consumption and the software can alert users when they stray from a desired path.