iPhone Tracker uses data stored in your data backups to plot where you have been on a map.
Ever wondered what sort of data is stored in your iPhone? iPhone Tracker can show you at least some of it, by accessing location data that is stored when you sync your iPhone with iTunes on a Mac.
iPhone Tracker is very simple - just open the zip file and double click. The app will then load a map of the world, and plot all the locations it finds in the folder /Users//Library/ApplicationSupport/MobileSync/Backups/.
The iPhone Tracker map can be zoomed into, to reveal more detailed data plots. There is a Play button, which plots the locations as they were recorded by your 3G iOS device. Not all your movements are recorded in this folder. iPhone Tracker shows you evidence of location based on 3G networks and WiFi. The second is much less accurate, meaning you may see places you haven't actually been! If you have traveled and turned off 'Data Roaming' and not connected to WiFi, no data will be found for these trips.
iPhone Tracker shows you with varying degrees of accuracy where your phone has been since iOS 4 was released. If the existence of this data worries you, you can enable 'Encrypt iPhone backup' in iTunes, which will ensure anyone on your Mac can't see your location data.