nice add-on Rated 3 out of 5 stars
This is a great add on. It does exactly what it says. I've had two issues I have come across.
1. I often open a split when I'm simply trying to use the vertical scroll bar.
2. When this happens in a pop-up window that has no tabs, there is no close button to click to remove the split. If I close the pop-up window and reopen from the link that creates the pop-up window, the split stays there. I have to completely close firefox to get rid of the split.