I'm looking for an app that would allow me to draw on images. I'm a teacher and I use my ipad to give presentations. For geography I want to be able to display a map and then draw lines or circles to show migration patterns or the like. I use goodreader to display my slideshows but that doesn't let me edit anything. So is there an app that allows me to present and edit slides or a standalone app that I could open just to draw? I've heard keynote was good but is not compatible with office 2007.