Does what it says. The about:config flag "accessibility.blockautorefresh" was not working on independent.co.uk for me for some reason (thought it works fine for other sites such as buzzfeednews.com), and this add-on is doing the job just great. Thanks!

ETA: There is one problem though, the add-on also disables manually reloading/refreshing black listed sites/domains. I suppose it's easy enough to just load a duplicate tab and close the original, but not quite ideal. Ymmv.