The Hayden Speller, or Hayden:Speller, checks Word and MacWrite
documents against a dictionary "covering 97% of the most frequently
used words in the English language."
A later version, 1.2c, was reviewed by Macworld in July 1986:
> Compared to the other programs tested, Hayden:Speller is neither
> particularly fast nor particularly effective. Because of its small
> dictionary (22,000 words), many correctly spelled words are flagged
> as possible misspellings, slowing down the checking process
> considerably. In addition, you may waste a good deal of time trying
> to determine if a suspect word is indeed misspelled or if it is
> merely not included in the dictionary.
>
> Hayden:Speller's main advantage is that its dictionary takes up
> comparatively little disk space and can therefore be used on a 128K
> Mac with a single drive.
