Introducing Narrable for Teachers. If you are an educator, and already have Narrable, you can upgrade. If you never signed up for Narrable, sign up, and then upgrade. Educators have access to unlimited Narrable presentations for FREE! Narrables can be shared using social media, embedded, and emailed.
They are in the process of creating Narrable + EDU, where your students can have accounts, log-ins with no email, collaborate,etc.... This will be a premium version, and will cost $49 a year.
I know there are tons of digital storytelling tools out there, but I think this one is worth a look! (The example above was embedded from the Narrable website.)