I'm semi-competent with software I've used to create material for my classes - PowerPoint, video editing, DreamWeaver, and so on. I have material I want to offer online for students to use outside of class. Many of them use iPhones and tablets. What software is useful for creating material useful across platforms? I just did a ppt with images and audio, but the download time and inability to make it open in browsers made it less user friendly than I need it to be. Any suggestions?