Presentation.io: Sync Your Presentations To Your Audience’s Laptops and iPads

Presentation.io is a new service that is designed to help your audience follow along with your presentations, allowing the members of your audience to see your slides on their laptops, iPads, and Android tablets and watch them change when you advance your slides.

http://www.freetech4teachers.com/2013/02/presentationio-sync-your-presentations.html