Organic Maps is a free Android & iOS offline maps app for travelers
Accurately Locate Smartphones using Social Engineering
Traccar GPS Tracking System
Lightweight GPS Logging Application For Android
A virtual location tool implemented using the Android debugging API
A high-performance, feature-packed library for all your mapping needs
Free Public Transport Assistant without Ads or Tracking
GPS log file viewer and analyzer
Viking is a free/open source program to manage GPS data
GPS navigation software for Windows Mobile & WinCE devices.
... the open-source glide computer
A Guide of the Trees of Barcelona City
GPS track editor for editing tracks and planning (multiple) day tours
GPX viewer, analyser and editor with official maps, terrain and graphs
Simple GPS tracking server
A Matlab software to estimate Euler pole parameters
Open source system for GPS tracking devices
Create, edit view GPX tracks (in the background - online maps)
Minimalistic wide-open GPS-locator/tracker
NMEA 0183 library for Java
Advanced mission simulation and analysis tool
Tool to work on map data, to check the data and generate your own maps
Plugins for OpenCPN