iMovie
iMovie is a handy app for compiling videos, photos, and music to created a "movie". iMovie also has 14 predesigned templates for creating short and dynamic movie trailers.
Being an Apple product, iMovie is not available on chromebooks; however, students can save pictures and videos to their Google drive on the chromebook, then open Google drive on an iPad, and save the photos from their drive onto the local camera roll.
Here is an overview for how to plan and create an iMovie trailer:
Link to a Blog post by Tony Vincent with iMovie trailer templates. Excellent for planning!