f.lux- a program that dims your computer monitor in accordance to the current time, making later-night browsing easier on the eyes. http://justgetflux.com/
AdBlock Plus- blocks ads, plain and simple. Chrome: https://adblockplus.org/en/chrome. Firefox: https://addons.mozilla.org/en-us/firefox/addon/adblock-plus/
Youtube Magic Actions- aside from a cheesy name, it offers the ability to change volume for YT vids by scrolling, a backlight that makes videos look a bit like movies, and other stuff. Chrome: https://chrome.google.com/webstore/detail/magic-actions-for-youtube/abjcfabbhafbcdfjoecdgepllmpfceif.... Firefox: http://magic-actions-for-youtube-firefox.en.softonic.com/
startpage.com- in light of the recent exposure of the unconstitutional NSA spying and the existance of PRISM, this is a solid alternative search engine to Google. Here's how it can use Google's results while offering you privacy: https://startpage.com/eng/prism-program-exposed.html. Link: https://startpage.com/eng/?
NotScript(s)- allows you to block plug-ins and other things from different sites when web browsing. Chrome: https://chrome.google.com/webstore/detail/notscripts/odjhifogjcknibkahlpidmdajjpkkcfn?hl=en. Firefox: https://addons.mozilla.org/en-us/firefox/addon/noscript/.
https everywhere- browser extension that encrypts communication s with many major websites. Both: https://www.eff.org/https-everywhere
hola- lets you access sites that may be blocked by your country. Also claims to allow faster browsing. Both: http://hola.org/
Co-op Adventure Tips & Tricks and Amazing Lab Idea- Now with Brackets Mentioning Kudos Count!