Next to each entry in the list on MyAnimeList you'll see (by default) three links leading to KissAnime. In short the userscript sends the title of the anime as a search query to KissAnime and opens the page in a new window.
As of version 1.6 there are also links added to an anime's description page as seen below.
Clicking on "KissAnime" will most of the time bring you to the search page on KissAnime with listings that has the title name in it. Clicking "(sub)" will most of the time bring you to the subbed stream for that anime. Clicking "(dub)" will most of the time bring you to the dubbed stream for that anime. Clicking either "(sub)" or "(dub)" will return no result if they have not specified if the stream is for subbed or dubbed on KissAnime.
There's also a small settings popup for hiding some buttons and stuff.
This script was originally posted on greasyfork