There's an app I've been recommending to just about everyone recently: iWordQ by Quillsoft. This is an iPad version of the powerful wordQ word processing software, combining word predication with the built-in voice-to-text capability of iPad 3, 4, and mini. At only $25, it's a true bargain for the capabilities of the app, and especially when compared to the $300 price tag of the computer version of wordQ+speakQ.
Writing: First and foremost, this app helps users of all ages to write. As you begin to type letters, up to 5 words will appear above the keyboard, predicting the word; after selecting a word, the app predicts what might come next. The word prediction is very good, based on a billion-word analysis, and also offers some "creative spelling" prediction for when misspellings happen mid-word. Usage cases appear next to some words, allowing you to see how a word is used, helpful for differentiating homonyms. The app also allows for abbreviation-expansion, so common phrases can be typed with just a few keystrokes. Both individual words and sentences are pronounced after they are typed, giving the user immediate feedback for proofreading. For words that a user cannot think how to spell, or for users just building or regaining literacy skills, use the microphone button on the keyboard to dictate the word or sentence with a newer device.
Reading: Once a document has been written or pasted in, iWordQ does it's second task - reading. In read mode, you can tap any word to hear it aloud, or swipe across multiple words to hear a phrase or passage. Sentences can be played individually or continuously. Turn on the "text chunking" option to parse the passage into breath-sized chunks. The app's help screen gives great advice on using these features for reading out loud (the app can be a teleprompter!), proofreading, and reading silently.
Options: The voice output can be male or female, using the popular Acapela voices Ryan and Heather. The app allows you to turn off the iPad's own auto-correction and spelling suggestions - a good idea for most users. You can add personalized words and pronunciation exceptions as well. Documents can be emailed, synced to Dropbox, printed, copied or sent as a message, Facebook post, or tweet. There are no formatting options in iWordQ, so it may be necessary to import the documents into Word or Pages if advanced processing features are needed. iWordQ comes in 3 varieties of English (US, Canada, and UK) as well as 2 French versions.
I use this app with people with aphasia who are working on functional writing. With reading skills often better than writing abilities, the word prediction is very helpful. One client had been using dictation software, but found he was more accurate with typing than speaking - now this app helps him combine writing and speaking to create his document. iWordQ can also be used with special needs students who struggle with spelling and grammar, reading back what's been written for use of auditory self-monitoring. You could use this app to focus on rate of reading with dysarthria or fluency clients, and there are several language lessons built-in to the usage examples (look for the triangle next to the predicted word). I first saw the PC-based version of this app in the Assistive Technology department of a rehab hospital, used because it saves so many keystrokes and allows voice typing for those with physical access issues. Now those same users can access this powerful tool conveniently and more affordably from their tablets.