Helptrix Author provides possibility of spell checking using MS Word dictionary. It of course means necessitate of installed MS Word on your computer along with proper language dictionary. However, spelling works only with  Select Spelling from the Edit menu or use shortcut F7.

Figure 3.50. Edit menu

Figure 3.51. Spell checking window

On the left side is displayed paragraph with the misspelled word highlighted by blue background. In the text box on the right side is displayed misspelled word. You can edit it, or click on one of suggestions in the list (suggestion will appear in text box). Click Replace button to fix misspelled word (will be fixed with word currently displayed in text box), or click Skip button to leave this word as it is and continue. Click Stop button to cancel spell checking completely. Instead of clicking on Replace button you can just double-click on one suggestion in the list for the same result as well.