Came across an interest bookmarklet to invoke Firefox’s built in spell checker everywhere on a website. It’s quite easy to install. Just drag this SpellCheck bookmarlet to your bookmarks toolbar and presto. With one click the entire page gets spell checked. You can even right click on highlighted words to get suggestions.
There are some limitations. Once you click the bookmarklet links will cease to work. Although a quick reload of the page will bring it back to normal. Also spell check suggestions don’t seem to show up in certain areas of your page which utilize popup content. I haven’t yet figured out how to trigger the popup and then click the bookmarklet because as soon as I leave the popup area to head towards my bookmarklet the popup disappears. Still this simple bookmarklet has already fixed countless errors on my pages simply and effectively.