GPSRecorder

GPSRecorder turns your iPhone in a GPS tracker and recording device. Use it:

• to record your position,
• to record your moves, 
• to geotag your external pictures.

While recording, the app just gives you your current latitude, longitude, distance and duration of record.

You can afterwards review your previous tracks on your phone, including map, distance and speed travelled, or export one as a GPX file for use with other software (GPX is lingua franca for locations), for example for geotagging pictures taken with an external camera.

Continued use of Location Services running in the background can dramatically decrease battery life, so there is an economy mode that will only record notable changes (usually several kilometers away).