20 best iPhone apps to get you started

Here's a selection of some essential and not-so-essential apps that will help you get by in a world increasingly dependent on digital interaction. 

4. Khan Academy


Khan Academy is unbelievable, Bill Gates said in 2010. The online trove of more than 3,800 education how-tos was ported to the smart phone world early last year.

Users can browse 10- to 15-minute videos showing creator Salman Khan and others doodling away on a digital black board to explain subjects from making hexaflexagons to the stereochemistry of dienophile.

Khan Academy also features new videos that help explain issues the world faces today – like a four-part series on the Greek debt crisis or the introduction to the US social security system.

Khan Academy’s videos hosted on YouTube have received more than 200 million hits.

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