Try your hand at some creative double exposures.
Could be a great art activity - have students fill a silhouette with another image. (Hands or head or body filled a place or action...)
"A double exposure image is two images merged or blended together into a single surrealistic photograph. On mobile devices, creating a double exposure effect is even easier, thanks to the number of photo apps available dedicated to the task. [Try] the Fused app from Easy Tiger Apps, one of these easiest ones to use on an iPhone. Not only does it do its magic on photos, but it works with videos, too!