Available on the Windows Phone Store and as source code on its GitHub project.

Breadcrumbs is a GPS map for Windows Phone designed for real-time tracking of your adventures.

Features:

• Record your movements and view on a map (good for retracing your steps!)
• Saves tracks as GPX files
• Sync GPX files with OneDrive
• View your current position in latitude, longitude, altitude, speed, heading, and GPS accuracy
• Keep the lock screen from opening (useful for mounting on your car or bike)
• Can run in the background with the screen off (useful for hiking)