...The GUI plots the GPX track (latitude vs longitude) and lets the user remove GPS points from the beginning and end of the track respectively. There is also a built-in Command Line Interface.
Note: No development anymore since I found out that GpsPrune does all the things I was looking for.
Convert a "line string" from a .kml file to a "route" in another .kml file. I started this project to use google maps for routing at home and a very simple GPS-device for following the route while on the road.