How many times have you been sitting through a presentation and wondering just how much longer it's going to last? How many times have you given a presentation and your audience has wondered the very same thing? Putting a simple number on your slides doesn't work since that only tells your audience how far you've gone, but now how far you've got left to go.
Numbering your slides with the total ("Slide 4/5000") is better, but you might as well have a little fun while doing it. So instead you can easily add in a man running across the screen. Or a balloon floating up to pop on a nail. Or, if you want to be very buttoned down, yes, just a bunch of numbers.
Slide Runner is available immediately for $0.99 in the Mac App Store. More info and a watermarked demo copy are available at http://www.bassetsoftware.com/sliderunner/