And if an iPad is too expensive, ChromeBooks are relatively affordable, and provide access to many of the same AT functions through Google apps/extensions. Some of them are free, and many of them are already licensed by your school. For example, in our secondary school building (which has universal ChromeBook adoption), we've turned on Google Read&Write for every student, which allows text-to-speech, speech-to-text, and word prediction. Text-to-speech function of Read&Write is free inside GoogleDocs, and teachers can get the premium version free (unfortunately not homeschool teachers). There are others, too, if you poke around the Chrome extensions.
