Wolfram Alpha, the "computational knowledge engine" has been ported from a website that can provide cool data results to certain queries to a £30 app for iPhone and iPod touch owners.
For £30, you get access to all of the knowledge that the website searches today. You can ask Wolfram Alpha to compute plain-language problems as diverse as "mother's father's nephew" or "9 years six months twelve days from yesterday" or even "population density United States vs France".
The app, which requires iPhone OS 3.0 or later, displays Wolfram Alpha's standard high-quality charts and graphs, with the overall experience customised for the iPhone. A special, nearly full-screen keyboard makes it easier to type in those maths queries that boggle the mind, and could position the app as a rival for some graphing calculators.