Wolfram Alpha is a very clever analytical research app available for iphone, ipod touch and ipad.
The app is integrated with its website and will answer queries relating to statistical, factual and scientific information in no time. For instance: which country has the world largest population or how much calories are there in a bowl of an ice-cream. Wolfram Alpha is a well designed app with user friendly interface and simplified menu buttons. I sometimes use Wolfram Alpha calculus problems and crossword puzzles and it is really mind-blowing to see the data presented really accurately.
And just for 1.99$ this amazing app will answer and solve almost everything and anything you ask under the sun.
Developer: Wolfram Alpha LLC