During WW2 all of the sides used poster campaigns to help boost moral and in this app you can find all of the British posters.
The set Wallpaper doesn't work very well this is experimental.
You can now share the poster to Social media sites.
Get the paid version of the App which contains The posters information https://play.google.com/store/apps/details?id=uk.co.cpmarkwell.britishww2postersfull