Is it possible to change slides in dual screen mode by clicking the slide on the left monitor? For instance, if the slide view is on the left screen, and the full-screen is on the right screen. I could do this on windows, but cannot see how to do this with Ubuntu.
I'm pretty sure that one way to do this is to show the same image in both monitors - if that would work for you. I have recently switched from Open Office to Libre Office on my machine that has a second monitor attached. The version of Impress in Libre Office certainly works this way.
However, another interesting option offered by Libre Office is the add-on "presenter console". This let you show the main presentation on the second screen (or LCD projector) and, on the main screen, shows the current slide, a mini-view of the next slide, some timing information (clock, presentation run time), previous/next buttons, a button to access any speaker's notes, etc. All this - but - you can't change the slide by clicking on the image; you have to use the next button. And, I don't think that you can use the mouse to point to something on the presentation screen in this mode.