Also on the to-do list. Allow multiple calls to the API in order to fill in the blanks of a list of words created during the course of personal reading or movie watching. This way I can keep track of the words I am learning and not have to do the footwork of looking for the word.
A central place to store the list is also something I would like to experiment with. Evernote is the first application, crossing over the mobile-desktop boundary seamlessly.