Would it be a Franklin Speller that you are thinking of, Karen? It would do the kind of thing you describe here. Of course, in this day and age, I am guessing "there's an app for that!" In any case, the idea of allowing students who have a disability that impacts on their spelling to make use of technology in their academic work is a sound practice. The student is still responsible for producing an acceptable quality of response. They just reach that level of quality through a different route!