FineScanner Pro
http://www.abbyy.com/finescanner_ios/
FineScanner Pro allows you to snap a picture of text and run high quality OCR right on your iPhone. The text can then be "opened in" Voice Dream Reader. Photos of your document must be taken within the FineScanner Pro app - you may not import a photo for OCR.
Scanbot
Scanbot is an alternate scanner/OCR app that has an educational version (no in app purchases). While it isn't quite as refined as FineScanner or Prizmo for text to speech usage, it does provide a spectacular scan that you can read in app using Apple's text to speech features for very little cost.
Prizmo
http://www.creaceed.com/prizmo
Prizmo provides an all in one snap, OCR, and text to speech option. The quality of the OCR is high. The voice quality is not my favorite. It is fast, however. To date I have not found an easy way to send text from Prizmo to Voice Dream.