Geospoof od jorrodev

Geospoof will create a new panel in you Development tools that will allow you to control the location provided by Geolocation API.
You can set the location by map, coordinates or reproduce a GPX track.
You will need to provide a OSM tiles URL to be able to use the extension, e.g:
https://{a-c}.yourser.ver/x/y/x/?key
This is a development extension it is not meant to be a privacy extension to not reveal your real geolocation.
The spoofed position it only will work as long as the developer tools are opened and activated from the Geospoof panel.