This feature was available on opera as a deep blue circle with an arrow inside. I have used it for about four months and then one day it just suddenly stopped working. I guess that happened after an update or so but cant be sure what was the exact reason. In opera there was also a setting to change the sensitivity of this gesture. I also get it when I reinstall opera in my PC but it only works at the first launch of the browser. Then closing the browser and re-opening it makes this feature disappear with it's settings. This must be a bug or some incompatibility issue with the OS which the developers are not fixing for a while. I don't know the reason behind this. I am using opera for about eight years and it is very difficult to switch to other browsers for me. Opera has always been the most feature-rich browser as I ever experienced. I would be very happy to see this useful feature back again.