I LOVE StoryBoard That as an engaging tool for digital storytelling. And a teacher's account is FREE, though it only provides three pane stories. You can work around that by having students save multiple three-pane storyboards as pdfs and putting them together in a Google Doc. I have used this app for years and students LOVE it.
Click here to access a host of lesson plan ideas across all content areas and all grades.
Project Ideas:
Ice Breakers/Introductions
Diagram a Process
Differentiate Instruction