GPX Viewer is a simple program to visualize a GPX file. It uses libchamplain and cairo for the plot. It can show multiple GPX files, show waypoints and multiple tracks per GPX file, highlight a selected track, show a speed vs. time graph, and show distance, duration, average, moving average, max speed, moving time, and GPS points. It supports zooming, smoothing of the speed graph, and highlighting points in a speed graph on a map.
