Puts personalized-spelling on form inputs you have allowed — and on no others.
You choose certain form inputs on certain sites. personalized-spelling is not watching the web. Once you opt in, that form gets the regular spellcheck: the same checks, the same one-click fixes, the same personal dictionary. Nothing else about the site changes. Submit is not blocked.
It docks beside the form (the default). A + on that form's side opens the suggestions; click again to make it small on the side. Several allowed forms on one page each have their own +.
