WolframAlpha is the ultimate information app for your Android tablet.
This app is basically an encyclopedia, dictionary, thesaurus, calculator, and a dozen other things all rolled into one. Search for any subject and see everything from synonyms to crossword puzzle clues, words that rhyme, or even word frequency throughout history.
There are plenty of apps that offer similar services for free, but none that are so comprehensive and put all those services in one easy to use place. I would probably have killed to have this app throughout school; it’s pretty much the ultimate education aide. The large screen of a tablet makes the keyboards easy to use, and it makes good use of the space. This is just an excellent app all around.
The WolframAlpha app is a marvelous resource for Android tablet owners.