Educational Technology Guy:
"SlidePresenter is an online presentation service. It has a free account that is full-featured and the service allows you to create videos that are synced with PowerPoint presentations. It is similar to Knovio.
SlidePresenter can be used to create presentations for use by educators in the classroom that can then be reviewed by students at a later date for review or reinforcement or to create training sessions that people can view on their own time. Students can also use it for class projects.
The free account limits videos to 15 min (similar to most of these services) but that is a good way to make sure your presentation is focused and concise. Each presentation can be tagged, embedded in other sites, and easily shared via social media."