Put these files on your server.

For example, on my server I put gps.php on http://herverenault.fr/gps
and the i-am-here* files on http://herverenault.fr/self-hosted-gps-tracker/demo/
So you can go to http://herverenault.fr/self-hosted-gps-tracker/demo/i-am-here
and see where the last user ran the demo.

Please note that these files are only provided as a starting point.
They should work out of the box on a regular Ubuntu server.
Taylor them to your needs if you like.

Important: if your Apache server is not configured with Multiviews
enabled, you have to add ".php" into the files.