This is a sample application that demonstrates how to load a google map using the GMapPanel in ExtJS. It shows how to load markers from a store and create a listener on the marker that can be listened for in the ViewController.
You MUST obtain a free google maps API key from here https://developers.google.com/maps/signup?hl=en
After you get the key update the index.html file with your key.
You can view more info at this blog post http://www.extjstips.com/2015/11/05/google-map-panel-gmap-and-loading-markers-from-a-store/
License GPLv3 https://www.gnu.org/licenses/gpl.html