Wapedia
For those who need to know it all, even Wikipedia isn't enough. That's why Wapedia is perfect: it gives you all of Wikipedia, in a quick and easy-to-understand format, and offers more reference options to search through like wikiquotes, wiktionary, and even more specialized wikis (Call of Duty, Mad Men, etc) for the most specific information you can glean from in an app. You can go find information by searching (which mimics Google Instant-ify auto searches) or browse what's "in the news" or flip through random and popular articles. Basically, it's the perfect search engine to find user-generated information about as many topics as possible.Free, Android.
Trivia Burst
Sure, maybe your friends hate you for always correcting them, but they absolutely love you when you're on their team for trivia games. Download Trivia Burst, an Android trivia game, so you can show off your know-it-all brain in a more playful setting while still feeding your ego. There's 22,000 different questions in 22 categories, so you're bound to impress someone with that big brain of yours. Free, Android.
Howcast
Howcast gives you very useful how-to videos that teach you how to do something. Nothing beats watching someone show you how it's done. How to jump start a car, separate an egg, pick a lock…pretty much anything, really. Free, Android
OTHERS TESTED:
• Google Sky Map: Nothing quite shows off knowing it all as much as knowing everything about the sky, the stars and various constellations. Plus, it makes you look like a dreamer
• Factbook: Gives information about countries from the CIA World Fact Book and United Nations data and statistics. Knowing fun facts about the world is important, you know.
• Wikidroid: Does Wikipedia, quick and fast.
• Dictionary.com: Not only does it define words, it gives audio pronunciations so you'll never flub something again
• Wolfram Alpha: Another level of nerditude, Wolfram Alpha gives you expert knowledge and life understanding on the go. $1.99
• Urban Dictionary: Stay up to date with all the slang and internet lingo people say these days.
Fuente: http://gizmodo.com/5714773/the-best-apps-for-people-who-need-to-know-everything