Now that ScribblePress isn't free, this is a great alternative for elementary digital storytelling. Little Story Maker lets students incorporate images from the photo roll as well as record their own audio with their stories - all for FREE.
This app, intended as a way for parents to create narrated bedtime stories for their children, could be a great digital storytelling tool for a broader audience. Students can create a movie that incorporates clay-mation figures and their own narration. It's Free and has potential.
This app goes with the FREE service provided by littlebirdtales.com. Students can create stories with their own artwork and audio recordings either from an app or on the web. The completed tales can be downloaded as either a PDF or mp4 with audio.
Though not free ($1.99), this is almost like an entry level screencasting app where students draw and then tell the story about their drawing. Completed projects can be shared.