One of my favorite apps on the iPad is iMovie. It is the app I used the most last school year. In fact, I think I was using it so much students were losing interest. Then there was an update that included trailers. Students were then able to create movie like trailers over various topics we were studying.
I always wished students had a storyboard or planning sheet to complete before diving right into creating their trailers. Many times students would get a sheet of notebook paper and write out a plan. Other students would just start creating, and finish well before the trailer was to end. That will all be different this year thanks to Tech-Info-Maths T.I.M who has created, "Storyboard help sheets for trailers."