You can annotate PDF files, shrink text to fit on the screen, and customize how your notes are organized.

This text-to-speech app imports content from various sources and reads it aloud (web pages, PDF files, Word documents, PowerPoints, and more). It integrates with Dropbox, Instapaper, and Pocket.

Talking Scientific Calculator can read numbers, answers, and formulas aloud to you. It has two entry modes, and the entire app is accessible to VoiceOver users.

Shape Math uses pictures and shapes to help you do simple mathematic equations, calculate tips at a restaurant, or do mental math.

iWordQ helps struggling readers and writers through text-to-speech capabilities, text highlighting, and much more.

With over 150,000 words, Howjsay is the world’s largest English pronunciation dictionary.

This app offers voice search to let you look up a word without having to spell it.

You can view definitions and synonyms with dictionary.com and thesaurus.com, with no internet connection required.

AudioBooks allows you to listen to books. Some features include high-quality human recordings and access to all types of reading material.