PowToon is a great tool for creating animated videos online. The standard free version of PowToon is fairly limited (videos are limited to 45 seconds). Currently, PowToon is giving away 50,000 classroom accounts for free. The classroom accounts include 60 student accounts that will have access to PowToon's advanced features including longer export times.
PowToon provides a drag-and-drop editor for creating animated videos. The videos that you create feature digital paper cut-outs on a colorful background. Think of PowToon as an online tool for creating videos in the style made popular by Common Craft. PowToon provides drawings of people and objects that you can arrange on blank canvas. After adding your narration to the arrangement you can publish your video.
Here is a very quick PowToon that took 5 minutes to put together:
taken from http://www.freetech4teachers.com/2014/09/powtoon-is-giving-away-free-accounts-to.html?utm_source=feedblitz&utm_medium=FeedBlitzRss&utm_campaign=freetech4teachers#.VAa5f2S1Zh8