Idioms are one of the trickiest parts of the English language. Native speakers use them without thinking about them too much, but for language learners they often cause mix-ups and confusion. English Idioms Interactive is an iOS app from Cambridge English Online featuring 45 colourful cartoons illustrating some of the funniest English idioms, plus quizzes and information to help improve your knowledge and command of English idioms. The full app costs €1.99 but there is a 'lite' version with three idioms at each of the three levels.
This app is probably better suited to more advanced learners because even I (!) couldn't guess some of the idioms at Level One (I did get the one above though). Although the illustrations and quizzes are fun, what's really useful from a language learning viewpoint is the detailed information on each idiom. In fact, you don't even have to buy the app, because 30 of the 45 idioms are available for free on the Cambridge Online English website. And while you're at it, you should check out some of the other excellent resources they have for English learners.
Can you identify the idiom illustrated above? See answer here.