Good idea, only sometimes useful, as usually content is much shorter than the whole page length. It doubles time of scrolling and displaying of Google Maps and Street View lines, so I uninstalled it. Black and white list option is needed.
EDIT to answer: % wasn't shown on a map, but after a few tests, with the add-on switched on and off, I'm sure of the effect.
Thanks for the review and the ideas, but when I use Google maps or street view it doesn't show the percentage indicator. I will check again, but good to know.
