Wikidroid Plus Look up just about anything on Wikipedia, in an easy-to-read format for your phone. Even save articles to your SD card to peruse later.
Merriam-Webster's Pocket What's that word, that one just on the tip of your tongue? Find it hear, searching by text or audio, and get the word of the day while you're at it.
IMDb Movies & TV It's what's-her-name, in that movie? You know, with that guy? Find out who they were and what they were in with this simple app that lets you brows the Internet Movie Database with ease.
Google Play Books Find books for free or for more, read the highest literature or the trashiest pulp, from the comfort of your phone.
NYTimes for Android Stay up-to-date, online or off, with great journalism and writing in the NY Times on your phone.
Sky Map Name that constellation with Google Sky Map.