The most essential internet software after the browser... Rated 5 out of 5 stars
I discovered adblock plus many years ago inadvertently through a colleague at work and since that I can't image using the internet without it.
So many websites these days carry big, intrusive, distracting adverts, Adblock Plus does a great job at removing them so you never even knew they were there at all.
I'd highly encourage people to donate to the creators for this invaluable tool.