Dictionary.com is an app that has an integrated dictionary.
Use Audible to find and download spoken audio books, information, educational programming, and other spoken media (radio, TV programs, magazines and newspapers). Audible audio files are compatible with many audio players, mobile phones and streaming media devices, files can also be downloaded using Windows PC or Macintosh computers, and burned to a CD. Using the Audible App allows the user to download, play and store multiple titles on their mobile device. Various subscription levels and pricing are available.