In a nutshell, Rbutr lets you follow inter-website disagreements. Found great evidence or counter-arguments to an online article? Rbutr helps you connects the dots.
Though Rbutr in its original guise was available for Chrome only, it has since been added to Firefox too. And now, Rbutr is making it easier to for anyone to access the service with a platform-independent toolbar, which is accessed simply by adding rbutr.com/ to the start of any URL. No plugins needed.