ScrabbleScrobble_ChromeExtension is a project mainly written in JavaScript, it's free.
Chrome Extension for Scrabble Scrobble @ Wordsquared.com
Clicking on the scrabble icon in the address bar will load the extension.
Add board tiles to the text bar that you want to play off of.
Clicking scrobble will search the dictionary for playable words off the "board" tiles.
Needing Fixing: jGrowl Height Blank Tiles? Letter Values Prevent multiple ext loads