🚀 go-pugleaf

   The spelling checker built into WriteNow version 1 does all but the last 2
   of these things (I haven't tried version 2 yet):

>Speed: Nobody wants to wait around while the speller is doing its thing.
    If you were using a Z80 machine before, you'd like the speed in WriteNow.
    And it's faster than Word 3.02's, too.

>Context Display: seeing the word in its context.
    WriteNow video-inverts the word right in the document -- though to be fair
    I believe this is standard practise for built-in checkers.

>Easy lookup for suggested replacement: (i.e., not just one
>  choice but several words in the immediate vicinity)
    WriteNow's checker window provides a GUESS button.  Clicking it causes all
    the similar words it can find to appear AS BUTTONS themselves.  Just click
    the word you want.  Or click FORGET.  Or IGNORE.

>Ease in adding word to main dictionary: Yes, it used to be
>  fairly easy to add to the main dictionary rather than
>  creating alternate dictionaries.
    Click the LEARN button in the checker's window.  I've found this a very
    quick way to add plurals and possessives to the dictionary.

>Ability to mark words found by speller to locate them
>  in an editor: sometimes faster.
   Well, it doesn't attach anything to the word that would help you find it
   later -- but since it's work directly in the document anyway, and has in
   fact already found the location -- do you really need this?  The checker is
   a modeless dialogue, so you can alternate between it and the document with
   no difficulty.

>Ability to back up: Sometimes you change your mind on how to
>spell something, such as a transliterated name (Qaddafi, Kadaffi,
>Qadhafi--intifada, intifadah) or a word with more than one correct
>spelling (modeling, modelling).
    Since WriteNow's checker always advances from the current cursor position,
    and the dialogue is modeless, you only need to move up to the top (or in
    fact to anywhere you want) and click in the text.  The check will
    continue from there.

    Your only problem here is that if you've told it to ignore Qaddafi
    (because you consider it correct, but don't actually want it in the main
    dictionary) it will continue to ignore it, rather than landing on it for
    changes.

>..., would be
>to also locate repeated words, such as "the the," which is more
>of a typo than a grammatical error.

     Nice.  This I haven't seen.

>Now put all this into a desk accessory, make it dirt-cheap,
>and you'll have something.

     Try Thunder.  My brother, on a 6-year old Mac 512+, swears by it.