10 free and low-cost apps that may be especially helpful for individuals who find reading and/or writing challenging are recommended here by Paul Hamilton.  Some offer text-to-speech and others are appropriate for users with low vision.

1. TextGrabber
2. Dragon Dictation
3. Type on PDF
4. GoodReader
5. vBookz PDF Voice Reader
6. Nebulous Notes
7. AudioNote
8. Cloudon
9. Idea Sketch
10. Side by Side