Presentain is a new iPhone and Android app that generates a unique ID, which the presenter types into a laptop connected to a projector. The presentation is displayed on the screen, and audience members can follow along on their personal devices by accessing the URL. They can watch the slides on their devices, send questions to the speaker, participate in polls, and share slides on social networks. After the session, the app automatically creates a video that combines presentation slides with the speaker’s voice to create a “slidecast” which can be emailed to the audience, posted to the Web, or shared on social networks.