Britain's Imperial War Museum has launched a free new app featuring striking World War II posters. From a collection of 20,000, a select 30 posters can be explored in depth on the iPhone or iPad.

Marked by bold designs, humor, memorable slogans and patriotism, these vintage graphic designs include such classics as 'Keep Calm and Carry On,' 'Make Do and Mend' and those along the lines of 'Loose Lips Sink Ships.'

The app allows users to zoom into details and read background information.

Great British Posters from the Second World War Volume 1 was developed by Artfinder and can be downloaded for free from the App Store.