Older learners often code up simple games for our younger ones. E.g. Pin country names on a map of Europe with HTML5 and such... Younger ones are then well motivated when they know a peer created the game!!! Example configured by a 15 year old is attached as zip file. Simply unzip and open 'index.html'.
My motto is: "Flying is allowed, anytime, any place... so reach for the sky". I never underestimate my learners.