Yes, it is a GpsGate message that pops up, since the browser requires the user to click (to interact) with the browser to open the extra window.
Why can that be? Because the browser developers wants to save the user from large number of pop-ups on less credible sites.
If GpsGate opens the window successfully. no pop-up is shown.
If GpsGate fails to open the window, a pop-up is shown to have the user do a manually click.