GG-Tracker has been replaced by Simple OpenGTS Tracker. Google Maps now requires a subscription model which makes it unefficient to implement. Simple OpenGTS Tracker solves that issue by replacing Google Maps with OpenStreetMap.
More info here: https://sourceforge.net/projects/simple-opengts-tracker/
Archive of GG-Tracker: Demonstration
GG-Tracker can run standalone or integrated on an existing webpage. The application is built using the template framework Bootstrap which makes it fully responsive (fits on any screen). Also the supporting files for Google Maps, Streetview and Earth are 100% responsive.
See GG-Tracker live in action: http://tracker.eppenga.com/